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This book should be returned on or before the date last marked below. 


Edited by 


With an Introduction by Dr. Shapley 

Enlarged Edition 

with a complete, new section 
on atomic fission 


A Treasury of Science 










by Sir J. Arthur Thomson and Patricf^ Geddes 



TURTLE EGGS FOR AGASSIZ by Dallas Lore Sharp 31 


by Roger Bacon, Albert Einstein, Sir Arthur Eddington, 
Ivan Pavlov, and Raymond B. Fosdicf^ 



by Nicholas Copernicus 

PROOF THAT THE EARTH MOVES by Galileo Galilei 58 

THE ORDERLY UNIVERSE by Forest Ray Moulton . 62 

Is THERE LIFE ON OTHER WORLDS? by Sir James Jeans 83 

THE MILKY WAY AND BEYOND by Sir Arthur Eddington 89 



GEOLOGICAL CHANGE by Sir Archibald Geikf 103 


by The Reverend James B. Macelwane, S.J. 

LAST DAYS OF ST. PIERRE by Fairfax Downey 118 

MAN, MAKER OF WILDERNESS by Paul B. Sears 126 

WHAT MAKES THE WEATHER by Wolfgang Langeweische 132 




DISCOVERIES by Sir Isaac Newton 150 

EXPERIMENTS AND IDEAS by Benjamin Franklin 168 

1 EXPLORING THE ATOM by Sir James Jeans 175 

TOURING THE ATOMIC WORLD by Henry Schacht 200 


THE TAMING OF ENERGY by George Russell Harrison 218 



THE CHEMICAL REVOLUTION by Waldemar Kaempffert 248 


SCIENCE IN WAR AND AFTER by George Russell Harrison 257 


THE NATURE OF LIFE by W. J. V. Osterhout 273 


by Sir /. Arthur Thomson and Patric\ Geddes 


WHERE LIFE BEGINS by George W. Gray 307 


ON BEING THE RIGHT SIZE by /. B. S. Haldane 321 


by David Starr Jordan and Vernon Lyman Kellogg 
FLOWERING EARTH by Donald Culross Peattie 337 



by David Starr Jordan and Vernon Lyman Kellogg 387 

SECRETS OF THE OCEAN by William Beebe 395 

THE WARRIOR ANTS by Caryl P. Hastens 406 


by Raymond L. Ditmars and Arthur M. Greenhall 
ANCESTORS by Gustav Eckstein 426 




GREGOR MENDEL AND His WORK by Hugo lltis 446 

THE COURTSHIP OF ANIMALS by Julian Huxley 453 

MAGIC ACRES by Alfred Toombs 464 




by Charles Darwin 


MISSING LINKS by John R. Baker 491 


LESSONS IN LIVING FROM THE STONE AGE by Vilhjalmur Stefansson 502 



You AND HEREDITY by Amram Scheinfeld 521 

BIOGRAPHY OF THE UNBORN by Margaret Shea Gilbert 540 

How THE HUMAN BODY Is STUDIED by Sir Arthur Keith 551 






by Edward Jenner 

THE HISTORY OF THE KINE Pox by Benjamin Water house 582 

Louis PASTEUR AND THE CONQUEST OF RABIES by Rent Vallery-Radot 586 





THINKING by James Harvey Robinson 638 

IMAGINATION CREATRIX by John Livingston Lowes 650, 







ALMIGHTY ATOM by John J. O'Neill 741 

RELATIONS by Jacob Viner 751 

ATOMIC WEAPONS by J. R. Oppenheimer 760 




the methods used in preparing it. We envisaged the audience as the 
person without specialized knowledge; we accepted as our purpose to give 
some realization of how the scientist works, of the body of knowledge 
that has resulted and of the excitement of the scientist's search. One of 
us has endeavored to convey some of that excitement in his Introduction, 
On Sharing in the Conquests of Science. 

We realized that a group of random selections, however good in them- 
selves, would suggest little of the unity, the architectural quality of science. 
We spent some months therefore in organizing the material before we 
adopted a definite plan. The plan is evident from the titles of the major 
Parts: Science and the Scientist, The Physical World, The World of Life 
and The World of Man. The subdivisions carry through the plan in what 
seems a logical sequence. 

There followed a period of over a year during which several thousand 
books and articles were examined in the light of this general scheme. 
In making our selections we have tried to emphasize especially the status 
and the contributions of modern science, to the end that the reader can 
bring himself abreast of current progress. But in a few cases, we have 
gone back the better part of a century to find the right discussion. We 
have incorporated a number of biographical sketches of important scien- 
tists, among them Pasteur, Madame Curie, Leeuwenhoek, in order to give 
a glimpse of the personalities of scientific explorers. Also we have reached 
generously into the past and selected classics of science, which not only 
add flavor but also exhibit the work and workers who have done so much 
to guide and inspire our civilization. 

It has been found possible to avoid translations almost completely, since 
the whole range of modern science has been explored assiduously by 
English-writing people. Much assistance in the preparation of a volume 
of this sort comes from the American standard magazines, and the semi- 
popular scientific monthlies. They have provided for scientific writers an 
incentive to summarize their work or the special field concerning which 


they write, in a fashion that is comprehensive, and comprehensible to the 

We are also especially indebted to certain skillful scientific interpreters, 
among them the English school of writers which includes the Huxleys, 
Sir J. A. Thomson, Sir James Jeans, and J. B. S. Haldane. More than 
once we have turned to their writings in preference to the scattered, 
technical, fragmentary originals from which their synthetic pictures are 

Many important scientists are of course not represented in this collec- 
tion, either because their writings have not been on the appropriate level, 
or because in our judgment the reader can do better with another writer. 
Limitations of space have also shortened and compressed many of the 
selections. And since the volume is designed for the general reader and 
not for the specialist, except when he is also a general reader, the addition 
of references, technical footnotes and the similar apparatus of the serious 
student are omitted. 

We hope that the volume will justify itself in interest, and in instruc- 
tional value, whether it is opened at random, or is methodically read from 
beginning to end. For the reader who wishes to understand the full mean- 
ing of any selection in relation to its context, we suggest a perusal of the 
brief introductory notes at the beginnings of the main Parts. 

As a general reference book this volume should have definite value. 
For example, the attentive reading of Moulton, Jeans, and Eddington will 
provide an authoritative picture of the fundamentals as well as the recent 
advances of astronomy; and in short space the reader can obtain from 
Langewiesche a fair understanding of modern weather prediction. Several 
contributors make atomic structure or the past of man a well-rounded 
story. And in a single essay subjects such as the Metagalaxy, earthquakes, 
parasitism or Freudianism are each clearly summarized. 

Nevertheless, the reader should realize that this work does not aim to 
be encyclopedic in presentation. It is our hope that he will go further into 
the vast stores of available writings to get specialized knowledge of any 
branch of science that may interest him. 

A contribution toward the integration of science is, as we have said, 
one goal of this volume. We hope that it may be of particular value to 
the scientific worker himself. No one works effectively in more than 
one or two of the special fields. The average specialist is just as unin- 
formed about science remote from his specialty as is the general reader. 
A familiarity with other disciplines should not only be good entertain- 
ment, but instructive as to techniques and attitudes. But of most impor- 
tance, the scientific specialist, while reading abroad, is informing himself 


on the inter-fields of science, or at least on the possibility and merit o 
inter-field study. If this volume can assist in however small a way in the 
integration that seems essential to man's intelligent control of his own 
fabrications, it will have attained the desired end. 

Preface to the New Edition 


-** and world-disturbing consequences of the fission of uranium atoms, in 
this second edition of our Treasury, can be attributed in considerable 
part to several episodes, in modern scientific groping, that beautifully 
illustrate the interlacing of the various sciences. We now commonly under- 
stand that techniques devised by one science may carry over to another; 
that results obtained in the biological realm may provide a key to mysteries 
that shroud the inanimate. 

But were we prepared to find that the study of paleozoic plant fossil 
would combine with the theory of relativity to culminate in bombs that 
frighten our civilization? Half a dozen fields of science have joined to 
inaugurate the new age of atoms, rockets, radar and antibiotics. The 
specialties contribute to astonishing generalizations and to surprising 
end results. Perhaps our bringing of the varied classics of science into 
this one large volume is justified on the grounds that science, thought 
and life can be viewed as one integrated phenomenon. 

Before the somewhat alarming release of atomic energy was accom- 
plished by the nuclear physicists, there were underlying basic contribu- 
tions by astronomers, paleontologists, chemists, botanists, geologists and 
mathematicians. Some of the critical steps can be briefly cited: the 
discovery and interpretation of radioactivity fifty years ago; the use of 
the natural radioactivity of uranium and thorium to estimate the ages 
of geological strata; the deduction that the life of half a billion years 
ago required much the same quantity and quality of sunlight as we now 
receive; the conclusion by astronomers that no other source than that 
inside the atom could provide the required amount and duration of 
solar energy; the growing realization that the energy in the atomic 
nucleus, as liberated in the hot interiors of stars in accordance with the 
principles of relativity, was the major power source of the universe; and, 
finally, the application to uranium 235 of atom-cracking and power-re- 
leasing radiation, with epochal consequences. 

It has been a glorious build-up, involving the stars of galactic space and 
the atoms of the microcosmos, and ending in the urgent need that the 


social scientists and the practical citizens help to solve current problems, 
both those of saving ourselves from the danger of our own ingenuity, 
and those of capitalizing for the good of humanity the gains that are 
now possible through the advances of science. 

The two principal changes in the present edition are the considerable 
extension of the selection from Jeans "Exploring the Atom" and the 
supplement of several contributions relating to atomic energy. The reader 
should not be misled by the emphasis on uranium and plutonium into 
giving atomic energy exclusive credit for the atomic age. There are 
many other contributors to the scientific revolution. Those popularly 
known best are jet propulsion, radar, penicillin and sulfa drugs, rocketry, 
blood derivatives and numerous developments in electronic magic. 

But back of these modern evidences of human skill are the conquests 
of generations of scientific workers who could think giant thoughts 
and fabricate ingenious tools and theories without the rich accessories 
now at hand. They laid the foundations on which we build foundations 
for future builders. We hope that the Treasury of Science which recounts 
many of these adventures of the past and present, will continue to 
provide the reader with building material for his own constructions. 




On Sharing in the Conquests of Science 


JL through the damp woods back of Walden Pond with Henry Thoreau, 
checking up on the food preferences of the marsh hawk, and the spread 
of sumach and goldenrod in old abandoned clearings. It requires stamina 
to match his stride as he plunges through swamps and philosophy, 
through underbrush, poetry, and natural history; it takes agility of body 
and mind if one does a full share of the day's measuring and speculation. 

But no sooner have I left the Walden Woods than I am scrambling 
up the fossil-rich Scottish cliffs with Hugh Miller, preparing the ground- 
work of the immortal history of The Old Red Sandstone. With the 
wonderment of pioneers we gaze at the petrified ripple-marks that 
some shallow receding sea, in ancient times, has left as its fluted me- 
morial its monument built on the sand and of the sand, but nevertheless 
enduring. We break open a stony ball this Scottish stonemason and 
I a nodular mass of blue limestone, and expose beautiful traces o 
an extinct world of animals and plants; we find fossilized tree ferns, 
giant growths from the Carboniferous Period of two hundred and fifty 
million years ago and forthwith we lose ourselves in conjecture. 

And thea I am off on another high adventure, higher than the moon 
this time; I am entering the study of the Frauenburg Cathedral to 
help Nicholas Copernicus do calculations on the hypothetical motions 
of the planets. He is, of course, deeply bemused with that rather queer 
notion that it might be the Sun that stands still not the Earth. Perhaps 
he can demonstrate that the planets go around the Sun, each in its own 
course. Fascinated, I peer over his shoulder at the archaic geometry, 
watch his laborious penning of the great book, and listen to his 
troubled murmuring about the inaccuracies of the measured coordinates 
of Saturn. "There are, you know, two other big ones further out," I put 
in; "and a system of m#ny moons around Jupiter, which makes it all 
very clear and obvious." It must startle him no end to have me interrupt 



in such a confident way. But he does nothing about it. More planets? An 
incredible idea! Difficulties enough in trying to explain the visible, 
without complicating the complexities further by introducing invisible 
planets. My assistance ignored, I experience, nevertheless, a carefree 
exhilaration; for I have, as it were, matched my wits with the wisdom of 
the greatest of revolutionaries, and come off not too badly! 

Now that I am fully launched in this career of working with the 
great explorers, and of cooperating in their attacks on the mysteries of 
the universe, I undertake further heroic assignments. I labor in the 
laboratories of the world; I maintain fatiguing vigils in the mountains 
and on the sea, try dangerous experiments, and make strenuous expedi- 
tions to Arctic shores and to torrid jungles all without moving from 
the deep fireside chair. 

Benjamin Franklin has a tempting idea, and I am right there to lend 
him a hand. We are having a lot of trouble in keeping that cantankerous 
kite in the thunder-cloud, from which the electric fluid should flow to 
charge and animate the house key. "Before long, Sir, we shall run 
printing presses with this fluid, and light our houses, and talk around 
the world" but he does not put it in the Autobiography. I am clearly 
a century ahead of my time! 

Youthful Charles Darwin is in the Galapagos. The good brig Beagle 
stands offshore. He has with him the collecting kit, the notebooks, and his 
curiosity. He is making records of the slight variations among closely 
similar species of plants and animals. He is pondering the origin of these 
differences, and the origin of species, and the whole confounding business 
of the origin of plants and animals. I sit facing him, on the rocks beside 
the tide pool, admiring the penetration and grasp of this young dreamer. 
The goal of his prolonged researches is a revolution in man's conception 
of life; he is assembling the facts and thoughts, and in this work I am a 
participant! Nothing could be more exciting. Also I have an advantage. 
I know about Mendel and Mendelian laws, and genes and chromosomes. 
I know that X-rays (unknown to Darwin), and other agents, can 
produce mutations and suddenly create living forms that Nature has 
not attained. This posterior knowledge of mine enhances the pleasure of 
my collaboration with the great naturalist; and I need have no fear that 
my information, or my ethereal presence, might bother him. 

There is so much scientific work of this sort for me to do before some 
tormenting duty draws me out of my strategic chair. The possibilities 
are nearly endless. Like a benign gremlin, I sit on the brim of a test 
tube in Marie Curie's laboratory and excitedly speculate with her on 
that radioactive ingredient in the pitchblende; I help name it radium. 


With Stefansson and the Eskimos I live for months on a scanty menu, 
and worry with him about the evils of civilization. And when young 
Evariste Galois, during his beautiful, brief, perturbed life in Paris, sits 
down to devise sensationally new ideas and techniques in pure mathe- 
matics, I am right there with applause and sympathy. 

Whenever I pause to appreciate how simple it is for me to take an 
active part in unravelling the home life of primitive man, or observing 
the voracity of a vampire bat; how simple for me, in company with the 
highest authorities, to reason on the theory of relativity or explore with 
a cyclotron the insides of atoms, it is then that I call for additional 
blessings on those artisans who invented printing. They have provided 
me with guide lines to remote wonders highly conductive threads that 
lead me, with a velocity faster than that of light itself, into times long past 
and into minds that biologically are long extinct. Through the simple 
process of learning how to interpret symbols, such as those that make 
this sentence, I can take part in most of the great triumphs of the human 
intellect. Blessings and praises, laurel wreaths and myrtle, are due those 
noble spirits who made writing and reading easily accessible, and thus 
opened to us all the romance of scientific discovery. 

Have you ever heard an ox warble? Probably not. Perhaps it goes 
through its strange life-cycle silent to our gross ears. But I have seen ox 
warbles, and through the medium of the printed page I have followed 
their gory careers. The ox warbles to which I refer are, of course, not 
bovine melodies, but certain flies that contribute to the discomfort of 
cattle, to the impoverishment of man's property, and to the enrichment 
of his knowledge of the insect world. 1 

It required a declaration of war on this entomological enemy, by 
some of the great nations of the planet, in order to discover him com- 
pletely and entrench mankind against his depredations. It took a century 
of detective work on the part of entomologists to lay bare the ox warble's 
secret life. Now that I have the story before me, I can go along with the 
scientists and experience again their campaigns, their misadventures, and 
their compensating discoveries. I can see how to connect a number 
of separate phenomena that long were puzzling those gay pasture flies 
that look like little bumblebees; those rows of tiny white eggs on the 
hairs above the hoofs of cattle; the growing larvae, guided mysteriously 
by ancestral experience to wind their way for months through the flesh 
of the legs and bodies of their unknowing hosts; the apparently inactive 

1 The full story of the ox warble is buried in various technical government reports. But 
see a brief chapter on the subject in Insects Man's Chief Competitors, by W. P. Flint and 
C. L. Metcalf (Williams & Wilkins, 1932). 


worms in the cattle's throats; the large midwinter mounds, scattered 
subcutaneously along the spines of the herd; and eventually those ruin- 
ous holes in the leather, which have forced governments into aggressive 
action into defense-with-pursuit tactics for the protection of their eco- 
nomic frontiers. It is all clear now. During the millennia of recent geolog- 
ical periods a little fly has learned how to fatten its offspring on a fresh 
beef diet, and prepare its huge grub for that critical moment when it 
crawls out, through the hole it has made in the ox hide, and drops to 
the earth for its metamorphosis the change from a headless, legless, 
eyeless, dark childhood to a maturity of wings and sunlight. 

The curiosity the scientist strives to satisfy is thus sometimes im- 
pelled by economics; more often by the pure desire to know. Our 
black-on-white guiding threads, which you may call printed books, or 
recorded history, not only transmit the stories of ancient and modern 
inquisitiveness and the inquiries it has inspired, but they also report, to 
the discerning recipient, the inevitability of practiced internationalism. 
They transmit the message that all races of mankind are curious about 
the universe, and that, when free and not too depressed by hunger, men 
instinctively question and explore, analyze and catalogue. They have done 
it in all ages, in all civilized countries. They work singly, in groups, 
and increasingly in world-wide organizations. Science recognizes no 
impossible national boundaries, and only temporary barriers of language. 
It points the way to international cooperation. 

To more than the art of printing, however, do we owe the successes 
and pleasures of our vicarious adventures in science. We are also greatly 
indebted to those who can write and will write in terms of our 
limited comprehension. Not all the scientists have the facility. Some- 
times the talk is too tough for us, or too curt. They have not the time 
to be lucid on our level and within our vocabulary, or perhaps their 
mental intensity has stunted the faculty of sympathetic explanation. 
When such technical barriers shut us from the scientific workshop, it is 
then we like to consult with a clear-spoken and understanding inter- 
preter. We sit on the back porch of the laboratory, while he, as middle- 
man, goes inside to the obscurities and mysteries, to return occasionally 
with comprehensible reports. In listening to him we hear not only his 
voice, but the overtones o the master he interprets. I like these men of 
understanding who play Boswell to the specialist. They often have a 
gift greater than that of the concentrated workers whom they soften 
up for us. For they have breadth and perspective, which help us to 
get at the essence of a problem more objectively than we could even if 
we were fully equipped with the language and knowledge of the fact- 


bent explorer and analyst. The scientific interpreters frequently enhance 
our enjoyment in that they give us of themselves, as well as of the dis- 
coverers whose exploits they recount. We are always grateful to them, 
moreover, for having spared us labor and possibly discouragement. 

Perhaps the greatest satisfaction in reading of scientific exploits and 
participating, with active imagination, in the dull chores, the brave syn- 
theses, the hard-won triumphs of scientific work, lies in the realization 
that ours is not an unrepeatable experience. Tomorrow night we can 
again go out among the distant stars. Again we can drop cautiously 
below the ocean surface to observe the unbelievable forms that inhabit 
those salty regions of high pressure and dim illumination. Again we can 
assemble the myriad molecules into new combinations, weave them 
into magic carpets that take us into strange lands of beneficent drugs 
and of new fabrics and utensils destined to enrich the process of 
everyday living. Again we can be biologist, geographer, astronomer, 
engineer, or help the philosopher evaluate the nature and meaning of 
natural laws. 

We can return another day to these shores, and once more embark 
for travels over ancient or modern seas in quest of half-known lands 
go forth as dauntless conquistadores, outfitted with the maps and gear 
provided through the work of centuries of scientific adventures. 

But we have done enough for this day. We have much to dream about. 
Our appetites may have betrayed our ability to assimilate. The fare has 
been irresistibly palatable. It is time to disconnect the magic threads; 
time to wind up the spiral galaxies, roll up the Milky Way and lay it 
aside until tomorrow. 





been written. Many tales of wonder have been told by the great writers 
of the world. Yet it is common knowledge that the reality of modern science 
is more wonderful than the imaginative world of a Poe, a Wells or a 
Jules Verne. It is therefore unfortunate that the story has usually been told in 
long words, written down in forbidding tomes. Like Agassiz's monumental 
work on turtles, Contributions to the Natural History of the United States, 
described by Dallas Lore Sharp in the following pages, they are "massive, 
heavy, weathered as if dug from the rocks/' Yet there is amusement in 
science, excitement, profound satisfaction. It is fitting that our first selection 
should be an attempt to describe that feeling, The Wonder of the World 
by Sir /. Arthur Thomson and Patrick Geddes. 

Nor is science something esoteric, something mysterious and incompre- 
hensible to the average person. We are all scientists, as T. H. Huxley shows 
clearly, whether we are concerned with the properties of green apples or 
with finding the burglar who stole our spoons. And we are led to our con- 
clusions by "the same train of reasoning which a man of science pursues 
when he is endeavoring to discover the origin and laws of the most occult 
phenomena." One of the great scientists of the nineteenth century, as well 
as its greatest scientific writer, Huxley is well qualified to instruct us. 

The quality that sets the scientist apart is perhaps the persistence of his 
curiosity about the world. That is what causes him to bury himself in his 
laboratory or travel to a remote corner of the globe. Like Oliver La Farge, 
in Scientists Are Lonely Men, he may spend months or even years on some 
quest, seeming trivial yet destined perhaps to prove a clue to the origin of a 
race. Or like Mr. Jenks of Middleboro, in Turtle Eggs for Agassiz, he may 
spend countless hours beside a murky pond, waiting for a turtle to lay her 



eggs. In both these tales there is much of the excitement, the emotional and 
intellectual spirit of the scientific quest. 

It is not possible in brief space to describe all the aspects of that quest. 
But in The Aims and Methods of Science, a group of thinkers illuminate a 
few of its many complexities. A passage from Roger Bacon shows why he is 
considered one of the originators of scientific method. Albert Einstein asks 
and answers the question, "Why does this magnificent applied science, 
which saves work and makes life easier, bring us so little happiness?" Sir 
Arthur Eddington shows that again and again the scientist must fly like 
Icarus, before he finally reaches the sun. The passion of work and research is 
Ivan Pavlov's theme. In a final selection, especially pertinent today as men 
fight, Raymond B. Fosdick explains how the scientist cannot be bound by the 
borders of sea or land, how no war can completely destroy his international 

The Wonder of the World 


From Life: Outlines of General Biology 

4^. resolute thinking, tells us that throughout nature there is always 
something of the wonderful thaumaston. What precisely is this "won- 
derful"? It cannot be merely the startling, as when we announce the fact 
that if we could place in one long row all the hair-like vessels or capillaries 
of the human body, which connect the ends of the arteries with the 
beginnings of the veins, they would reach across the Atlantic. It would 
be all the same to us if they reached only half-way across. Nor can the 
wonderful be merely the puzzling, as when we are baffled by the "sailing" 
of an albatross round and round our ship without any perceptible strokes 
of its wings. For some of these minor riddles are being read every year, 
without lessening, however, the fundamental wonderfulness of Nature. 
Indeed, the much-abused word "wonderful" is properly applied to any fact 
the knowledge of which greatly increases our appreciation of the signifi- 
cance of the system of which we form a part. The truly wonderful maizes 
all other things deeper and higher. Science is always dispelling mists 
the minor marvels; but it leaves us with intellectual blue sky, sublime 
mountains, and deep sea. Their wonder appears and remains. 

There seems to be a rational basis for wonder in the abundance of power 
in the world the power that keeps our spinning earth together as it re- 
volves round the sun, that keeps our solar system together as it journeys 
through space at the rate of twelve miles a second towards a point in the 
sky, close to the bright star Vega, called "the apex of the sun's way." At 
the other extreme there is the power of a fierce little world within the com- 
plex atom, whose imprisoned energies are set free to keep up the radiant 
energies of sun and star. And between these extremes of the infinitely 
great and the infinitely little are the powers of life the power of winding 
-up the clock almost as fast as it runs down, the power of a fish that has 



better engines than those of a Mauretania, life's power of multiplying 
itself, so that in a few hours an invisible microbe may become a fatal mil- 

Another, also old-fashioned, basis for wonder is to be found in the im- 
mensities. It takes light eight minutes to reach us from the sun, though it 
travels at the maximum velocity of about 186,300 miles per second. So 
we see the nearest star by the light that left it four years ago, and Vega as 
it was twenty-seven years ago, and most of the stars that we see without a 
telescope as they were when Galileo Galilei studied them in the early years 
of the seventeenth century. In any case it is plain that we are citizens of 
no mean city. 

A third basis for rational wonder is to be found in the intricacy and 
manifoldness of things. We get a suggestion of endless resources in the 
creation of individualities. Over two thousand years ago Aristotle knew 
about five hundred different kinds of animals; and now the list of the 
named and known includes twenty-five thousand different kinds of back- 
boned animals, and a quarter of a million some insist on a minimum of 
half a million backboneless animals, each itself and no other. For "all 
flesh is not the same flesh, but there is one kind of flesh of men, another 
flesh of beasts, another of fishes, and another of birds." The blood of a 
horse is different from that of an ass, and one can often identify a bird 
from a single feather or a fish from a few scales. One is not perhaps 
greatly thrilled by the fact that the average man has twenty-five billions 
of oxygen-capturing red blood corpuscles, which if spread out would oc- 
cupy a surface of 3,300 square yards; but there is significance in the cal- 
culation that he has in the cerebral cortex of his brain, the home of the 
higher intellectual activities, some nine thousand millions of nerve cells, 
that is to say, more than five times the present population of the globe 
surely more than the said brain as yet makes use of. 

So it must be granted that we are fearfully and wonderfully made! Our 
body is built up of millions of cells, yet there is a simplicity amid the 
multitudinousness, for each cell has the same fundamental structure. 
Within the colloid cell-substance there floats a kernel or nucleus, which 
contains forty-seven (or in woman forty-eight) chromosomes, each with 
a bead-like arrangement of smaller microsomes, and so on, and so on. 
Similarly, while eighty-nine different elements have been discovered out 
of the theoretically possible ninety-two, we know that they differ from 
one another only in the number and distribution of the electrons and pro- 
tons that make up their microcosmic planetary system. What artistry to 
weave the gorgeously varied tapestry of the world out of two kinds of 


physical thread besides, of course, Mind, which eventually searches into 
the secret of the loom. 

A fourth basis for rational wonder is in the orderliness of Nature, and 
that is almost the same thing as saying its intelligibility. What implications 
there are in the fact that man has been able to make a science of Nature! 
Given three good observations of a comet, the astronomer can predict its 
return to a night. It is not a phantasmagoria that we live in, it is a rational- 
isable cosmos. The more science advances the more the fortuitous shrivels, 
and the more the power of prophecy grows. Two astronomers foretold the 
discovery of Neptune; the chemists have anticipated the discovery of new 
elements; the biologist can not only count but portray his chickens before 
they are hatched. The Order of Nature is the largest of all certainties; and 
leading authorities in modern physics tell us that we cannot think of it as 
emerging from the fortuitous. It is time that the phrase "a fortuitous con- 
course of atoms" was buried. Even the aboriginal nebula was not that\ No 
doubt there have been diseases and tragedies among men, cataclysms and 
volcanic eruptions upon the earth, and so on no one denies the shadows; 
but even these disturbances are not disorderly; the larger fact is the ab- 
sence of all caprice. To refer to the poet's famous line, no one any longer 
supposes that gravitation can possibly cease when he goes by the avalanche. 
Nor will a microbe's insurgence be influenced by the social importance of 
the patient. 

Corresponding to the intelligibility of Nature is the pervasiveness of 
beauty a fifth basis of rational wonder, appealing to the emotional side 
of our personality. Surely Lotze was right, that it is of high value to look 
upon beauty not as a stranger in the world, nor as a casual aspect of cer- 
tain phenomena, but as "the fortunate revelation of that principle which 
permeates all reality with its living activity." 

A sixth basis of rational wonder is to be found in the essential character- 
istics of living creatures. We need only add the caution that the marvel of 
life is not to be taken at its face value; as Coleridge wisely said, the first 
wonder is the child of ignorance; we must attend diligently to all that 
biochemistry and biophysics can discount; we must try to understand all 
that can be formulated in terms of colloids, and so on. Yet when all that 
is said, there seem to be large residual phenomena whose emergence in 
living creatures reveal a new depth in Nature. Life is an enduring, in- 
surgent activity, growing, multiplying, developing, enregistering, varying, 
and above all else evolving. 

For this is the seventh wonder Evolution. It is not merely that all 
things flow; it is that life flows uphill. Amid the ceaseless flux there is 
not only conservation, there is advancement. The changes are not those of 


a kaleidoscope, but of "an onward advancing melody." As the unthink- 
ably long ages passed the earth became the cradle and home of life; nobler 
and finer kinds of living creatures appeared; there was a growing vic- 
tory of life over things and of "mind" over "body"; until at last appeared 
Man, who is Life's crowning wonder, since he has given to everything 
else a higher and deeper significance. And while we must consider man 
in the light of evolution, as most intellectual combatants admit, there is 
the even more difficult task of envisaging evolution in the light of Man. 
Finis coronat opus a wise philosophical axiom; and yet the scientist must 
qualify it by asking who can say Finis to Evolution. 


We Are All Scientists 


From Darwiniana 

seem to suppose, some kind of modern black art. You might easily 
gather this impression from the manner in which many persons speak of 
scientific inquiry, or talk about inductive and deductive philosophy, or the 
principles of the "Baconian philosophy." I do protest that, of the vast 
number of cants in this world, there are none, to my mind, so contempti- 
ble as the pseudo-scientific cant which is talked about the "Baconian 

To hear people talk about the great Chancellor and a very great man 
he certainly was, you would think that it was he who had invented 
science, and that there was no such thing as sound reasoning before the 
time of Queen Elizabeth! Of course you say, that cannot possibly be true; 
you perceive, OIL a moment's reflection, that such an idea is absurdly 
wrong. . . . 


The method of scientific investigation is nothing but the expression 
of the necessary mode of working of the human mind. It is simply 
the mode at which all phenomena are reasoned about, rendered precise 
and exact. There is no more difference, but there is just the same kind of 
difference, between the mental operations of a man of science and those 
of an ordinary person, as there is between the operations and methods of 
a baker or of a butcher weighing out his goods in common scales, and the 
operations of a chemist in performing a difficult and complex analysis by 
means of his balance and finely-graduated weights. It is not that the action 
of the scales in the one case, and the balance in the other, differ in the 
principles of their construction or manner of working; but the beam of 
one is set on an infinitely finer axis than the other, and of course turns by 
the addition of a much smaller weight. 

You will understand this better, perhaps, if I give you some familiar 
example. You have all heard it repeated, I dare say, that men of science 
work by means of induction and deduction, and that by the help of 
these operations, they, in a sort of sense, wring from Nature certain 
other things, which are called natural laws, and causes, and that out of 
these, by some cunning skill of their own, they build up hypotheses 
and theories. And it is imagined by many, that the operations of the 
common mind can be by no means compared with these processes, and 
that they have to be acquired by a sort of special apprenticeship to the 
craft. To hear all these large words, you would think that the mind of 
a man of science must be constituted differently from that of his fellow 
men; but if you will not be frightened by terms, you will discover that 
you are quite wrong, and that all these terrible apparatus are being 
used by yourselves every day and every hour of your lives. 

There is a well-known incident in one of Moliere's plays, where the 
author makes the hero express unbounded delight on being told that he 
had been talking prose during the whole of his life. In the same way, 
I trust, that you will take comfort, and be delighted with yourselves, on 
the discovery that you have been acting on the principles of inductive 
and deductive philosophy during the same period. Probably there is not 
one who has not in the course of the day had occasion to set in motion a 
complex train of reasoning, of the very same kind, though differing of 
course in degree, as that which a scientific man goes through in tracing 
the causes of natural phenomena. 

A very trivial circumstance will serve to exemplify this. Suppose you go 
into a fruiterer's shop, wanting an apple, you take up one, and, on biting 
it, you find it is sour; you look at it, and see that it is hard and green. You 
take up another one, and that too is hard, green, and sour. The shopman 


offers you a third; but, before biting it, you examine it, and find that it 
is hard and green, and you immediately say that you will not have it, 
as it must be sour, like those that you have already tried. 

Nothing can be more simple than that, you think; but if you will take 
the trouble to analyse and trace out into its logical elements what has 
been done by the mind, you will be greatly surprised. In the first place, 
you have performed the operation of induction. You found that, in two 
experiences, hardness and greenness in apples went together with sour- 
ness. It was so in the first case, and it was confirmed by the second. True, 
it is a very small basis, but still it is enough to make an induction from; 
you generalise the facts, and you expect to find sourness in apples where 
you get hardness and greenness. You found upon that a general law, that 
all hard and green apples are sour; and that, so far as it goes, is a 
perfect induction. Well, having got your natural law in this way, when 
you are offered another apple which you find is hard and green, you say, 
"All hard and green apples are sour; this apple is hard and green, there- 
fore this apple is sour." That train of reasoning is what logicians call a 
syllogism, and has all its various parts and terms its major premiss, its 
minor premiss, and its conclusion. And, by the help of further reason- 
ing, which, if drawn out, would have to be exhibited in two or three other 
syllogisms, you arrive at your final determination, "I will not have that 
apple." So that, you see, you have, in the first place, established a law by 
induction, and upon that you have founded a deduction, and reasoned out 
the special conclusion of the particular case. Well now, suppose, having 
got your law, that at some time afterwards, you are discussing the qualities 
of apples with a friend: you will say to him, "It is a very curious thing, 
but I find that all hard and green apples are sour!" Your friend says to 
you, "But how do you know that?" You at once reply, "Oh, because I have 
tried them over and over again, and have always found them to be so." 
Well, if we were talking science instead of common sense, we should call 
that an experimental verification. And, if still opposed, you go further, and 
say, "I have heard from the people in Somersetshire and Devonshire, 
where a large number of apples are grown, that they have observed the 
same thing. It is also found to be the case in Normandy, and in North 
America. In short, I find it to be the universal experience of mankind 
wherever attention has been directed to the subject." Whereupon, your 
friend, unless he is a very unreasonable man, agrees with you, and is 
convinced that you are quite right in the conclusion you have drawn. 
He believes, although perhaps he does not know he believes it, that the 
more extensive verifications are, that the more frequently experiments 
have been made, and results of the same kind arrived at, that the more 


varied the conditions under which the same results are attained, the more 
certain is the ultimate conclusion, and he disputes the question no further. 
He sees that the experiment has been tried under all sorts of conditions, 
as to time, place, and people, with the same result; and he says with you, 
therefore, that the law you have laid down must be a good one, and he 
must believe it. 

In science we do the same thing; the philosopher exercises precisely 
the same faculties, though in a much more delicate manner. In scientific 
inquiry it becomes a matter of duty to expose a supposed law to every 
possible kind of verification, and to take care, moreover, that this is done 
intentionally, and not left to a mere accident, as in the case of the apples. 
And in science, as in common life, our confidence in a law is in exact pro- 
portion to the absence of variation in the result of our experimental veri- 
fications. For instance, if you let go your grasp of an article you may have 
in your hand, it will immediately fall to the ground. That is a very com- 
mon verification of one of the best established laws of nature that of 
gravitation. The method by which men of science establish the existence 
of that law is exactly the same as that by which we have established the 
trivial proposition about the sourness of hard and green apples. But we 
believe it in such an extensive, thorough, and unhesitating manner because 
the universal experience of mankind verifies it, and we can verify it our- 
selves at any time; and that is the strongest possible foundation on which 
any natural law can rest. 

So much, then, by way of proof that the method of establishing laws in 
science is exactly the same as that pursued in common life. Let us now 
turn to another matter (though really it is but another phase of the same 
question), and that is, the method by which, from the relations of certain 
phenomena, we prove that some stand in the position of causes towards 
the others. 

I want to put the case clearly before you, and I will therefore show you 
what I mean by another familiar example. I will suppose that one of you, 
on coming down in the morning to the parlour of your house, finds that 
a tea-pot and some spoons which had been left in the room on the previous 
evening are gone, the window is open, and you observe the mark of a 
dirty hand on the window-frame, and perhaps, in addition to that, you 
notice the impress of a hob-nailed shoe on the gravel outside. All these 
phenomena have struck your attention instantly, and before two seconds 
have passed you say, "Oh, somebody has broken open the window, entered 
the room, and run off with the spoons and the tea-pot!" That speech is out 
of your mouth in a moment. And you will probably add, "I know there 
has; I am quite sure of it!" You mean to say exactly what you know; 


but in reality you are giving expression to what is, in all essential partic- 
ulars, an hypothesis. You do not \nous it at all; it is nothing but an 
hypothesis rapidly framed in your own mind. And it is an hypothesis 
founded on a long train of inductions and deductions. 

What are those inductions and deductions, and how have you got at 
this hypothesis? You have observed, in the first place, that the window is 
open; but by a train of reasoning involving many inductions and deduc- 
tions, you have probably arrived long before at the general law and a 
very good one it is that windows do not open of themselves; and you 
therefore conclude that something has opened the window. A second 
general law that you have arrived at in the same way is, that tea-pots and 
spoons do not go out of a window spontaneously, and you are satisfied 
that, as they are not now where you left them, they have been removed. 
In the third place, you look at the marks on the window-sill, and the shoe- 
marks outside, and you say that in all previous experience the former 
kind of mark has never been produced by anything else but the hand of 
a human being; and the same experience shows that no other animal but 
man at present wears shoes with hob-nails in them such as would produce 
the marks in the gravel. I do not know, even if we could discover any of 
those "missing links" that are talked about, that they would help us to 
any other conclusion! At any rate the law which states our present experi- 
ence is strong enough for my present purpose. You next reach the conclu- 
sion, that as these kinds of marks have not been left by any other animals 
than men, or are liable to be formed in any other way than by a man's 
hand and shoe, the marks in question have been formed by a man in that 
way. You have, further, a general law, founded on observation and 
experience, and that, too, is, I am sorry to say, a very universal and unim- 
peachable one, that some men are thieves; and you assume at once from 
all these premisses and that is what constitutes your hypothesis that the 
man who made the marks outside and on the window-sill, opened the 
window, got into the room, and stole your tea-pot and spoons. You have 
now arrived at a vera causa; you have assumed a cause which, it is plain, 
is competent to produce all the phenomena you have observed. You can 
explain all these phenomena only by the hypothesis of a thief. But that is 
a hypothetical conclusion, of the justice of which you have no absolute 
proof at all; it is only rendered highly probable by a series of inductive and 
deductive reasonings. 

I suppose your first action, assuming that you are a man of ordinary 
common sense, and that you have established this hypothesis to your own 
satisfaction, will very likely be to go for the police, and set them on the 
track of the burglar, with the view to the recovery of your property. But 


just as you are starting with this object, some person comes in, and on 
learning what you are about, says, "My good friend, you are going on a 
great deal too fast. How do you know that the man who really made the 
marks took the spoons? It might have been a monkey that took them, and 
the man may have merely looked in afterwards." You would probably 
reply, "Well, that is all very well, but you see it is contrary to all experience 
of the way tea-pots and spoons are abstracted; so that, at any rate, your 
hypothesis is less probable than mine." While you are talking the thing 
over in this way, another friend arrives. And he might say, "Oh, my dear 
sir, you are certainly going on a great deal too fast. You are most presump- 
tuous. You admit that all these occurrences took place when you were 
fast asleep, at a time when you could not possibly have known anything 
about what was taking place. How do you know that the laws of Nature 
are not suspended during the night? It may be that there has been some 
kind of supernatural interference in this case." In point of fact, he declares 
that your hypothesis is one of which you cannot at all demonstrate the 
truth and that you are by no means sure that the laws of Nature are the 
same when you are asleep as when you are awake. 

Well, now, you cannot at the moment answer that kind of reasoning. 
You feel that your worthy friend has you somewhat at a disadvantage. 
You will feel perfectly convinced in your own mind, however, that you are 
quite right, and you say to him, "My good friend, I can only be guided by 
the natural probabilities of the case, and if you will be kind enough 
to stand aside and permit me to pass, I will go and fetch the police." 
Well, we will suppose that your journey is successful, and that by good 
luck you meet with a policeman; that eventually the burglar is found with 
your property on his person, and the marks correspond to his hand and to 
his boots. Probably any jury would consider those facts a very good 
experimental verification of your hypothesis, touching the cause of the 
abnormal phenomena observed in your parlour, and would act accordingly. 

Now, in this suppositious case, I have taken phenomena of a very com- 
mon kind, in order that you might see what are the different steps in an 
ordinary process of reasoning, if you will only take the trouble to analyse 
it carefully. All the operations I have described, you will see, are involved 
in the mind of any man of sense in leading him to a conclusion as to the 
course he should take in order to make good a robbery and punish the 
offender. I say that you are led, in that case, to your conclusion by exactly 
the same train of reasoning as that which a man of science pursues when 
he is endeavouring to discover the origin and laws of the most occult 
phenomena. The process is, and always must be, the same; and precisely 
the same mode of reasoning was employed by Newton and Laplace in 


their endeavours to discover and define the causes of the movements of 
the heavenly bodies, as you, with your own common sense, would 
employ to detect a burglar. The only difference is, that the nature of the 
inquiry being more abstruse, every step has to be most carefully watched, 
so that there may not be a single crack or flaw in your hypothesis. A 
flaw or crack in many of the hypotheses of daily life may be of little or 
no moment as affecting the general correctness of the conclusions at which 
we may arrive; but, in a scientific inquiry, a fallacy, great or small, is 
always of importance, and is sure to be in the long run constantly produc- 
tive of mischievous, if not fatal results. 

Do not allow yourselves to be misled by the common notion that an 
hypothesis is untrustworthy simply because it is an hypothesis. It is often 
urged, in respect to some scientific conclusion, that, after all, it is only an 
hypothesis. But what more have we to guide us in nine-tenths of the 
most important affairs of daily life than hypotheses, and often very ill- 
based ones? So that in science, where the evidence of an hypothesis is 
subjected to the most rigid examination, we may rightly pursue the same 
course. You may have hypotheses and hypotheses. A man may say, if he 
likes, that the moon is made of green cheese: that is an hypothesis. But 
another man, who has devoted a great deal of time and attention to the 
subject, and availed himself of the most powerful telescopes and the 
results of the observations of others, declares that in his opinion it is 
probably composed of materials very similar to those of which our own 
earth is made up: and that is also only an hypothesis. But I need not 
tell you that there is an enormous difference in the value of the two 
hypotheses. That one which is based on sound scientific knowledge is sure 
to have a corresponding value; and that which is a mere hasty 
random guess is likely to have but little value. Every great step in our 
progress in discovering causes has been made in exactly the same way as 
that which I have detailed to you. A person observing the occurrence of 
certain facts and phenomena asks, naturally enough, what process, what 
kind of operation known to occur in Nature applied to the particular case, 
will unravel and explain the mystery? Hence you have the scientific 
hypothesis; and its value will be proportionate to the care and completeness 
with which its basis has been tested and verified. It is in these matters as in 
the commonest affairs of practical life: the guess of the fool will be folly, 
while the guess of the wise man will contain wisdom. In all cases, you see 
that the value of the result depends on the patience and faithfulness with 
which the investigator applies to his hypothesis every possible kind of 
verification. . . . 


Scientists Are Lonely Men 


study of the science of ethnology, I corresponded with men in Ireland, 
Sweden, Germany, France, and Yucatan, and had some discussion with 
a Chinese. One by one these interchanges were cut off; in some countries 
the concept of science is dead, and even in the free strongholds of Britain 
and the Americas pure science is being must be set aside in favor of 
what is immediately useful and urgently needed. It must hibernate now; 
for a while all it means is likely to be forgotten. 

It has never been well understood. Scientists have never been good at 
explaining themselves and, frustrated by this, they tend to withdraw into 
the esoteric, refer to the public as "laymen," and develop incomprehensible 
vocabularies from which they draw a naive, secret-society feeling of 

What is the special nature of a scientist as distinguished from a soda- 
jerker? Not just the externals such as his trick vocabulary, but the human 
formation within the man? Most of what is written about him is rot; but 
there is stuff there which a writer can get his teeth into, and it has its vivid, 
direct relation to all that we are fighting for. 

The inner nature of science within the scientist is both emotional and 
intellectual. The emotional element must not be overlooked, for without 
it there is no sound research on however odd and dull-seeming a subject. 
As is true of all of us, an emotion shapes and forms the scientist's life; 
at the same time an intellectual discipline molds his thinking, stamping 
him with a character as marked as a seaman's although much less widely 

To an outsider who does not know of this emotion, the scientist suggests 
an ant, putting forth great efforts to lug one insignificant and apparently 
unimportant grain of sand to be added to a pile, and much of the time his 



struggle seems as pointless as an ant's. I can try to explain why he does it 
and what the long-term purpose is behind it through an example from my 
own work. Remember that in this I am not thinking of the rare, fortunate 
geniuses like the Curies, Darwin, or Newton, who by their own talents 
and the apex of accumulated thought at which they stood were knowingly 
in pursuit of great, major discoveries. This is the average scientist, one 
among thousands, obscure, unimportant, toilsome. 

I have put in a good many months of hard work, which ought by usual 
standards to have been dull but was not, on an investigation as yet un- 
finished to prove that Kanhobal, spoken by certain Indians in Guatemala, 
is not a dialect of Jacalteca, but that, on the contrary, Jacalteca is a dialect 
of Kanhobal. Ridiculous, isn't it? Yet to me the matter is not only serious 
but exciting. Why ? 

There is an item of glory. There are half a dozen or so men now living 
(some now, unfortunately, our enemies) who will pay me attention and 
respect if I prove my thesis. A slightly larger number, less interested in the 
details of my work, will give credit to La Farge for having added to the 
linguistic map of Central America the name of a hitherto unnoted dialect. 
But not until I have told a good deal more can I explain as I shall pres- 
ently why the notice of so few individuals can constitute a valid glory. 

There's the nature of the initial work. I have spent hours, deadly, difficult 
hours, extracting lists of words, paradigms of verbs, constructions, idioms, 
and the rest from native informants, often at night in over-ventilated huts 
while my hands turned blue with cold. (Those mountains are far from 
tropical.) An illiterate Indian tires quickly when giving linguistic informa- 
tion. He is not accustomed to thinking of words in terms of other words; 
his command of Spanish is so poor that again and again you labor over 
misunderstandings; he does not think in our categories of words. Take 
any schoolchild and ask him how you say, "I go." Then ask him in turn, 
"Thou goest, he goes, we go." Even the most elementary schooling has 
taught him, if only from the force of staring resentfully at the printed 
page, to think in terms of the present tense of a single verb that is, to 
conjugate. He will give you, in Spanish for instance, "Me voy, te vas> se va> 
nos vamos" &\\ in order. Try this on an illiterate Indian. He gives you his 
equivalent of "I go," follows it perhaps with "thou goest," but the next 
question reminds him of his son's departure that morning for Ixtatan, so 
he answers "he sets out," and from that by another mental leap produces 
"we are traveling." This presents the investigator with a magnificently 
irregular verb. He starts checking back, and the Indian's mind being set 
in the new channel, he now gets "I travel" instead of "I go." 

There follows an exhausting process of inserting an alien concept into 


the mind of a man with whom you are communicating tenuously in a 
language which you speak only pretty well and he quite badly. 

Then of course you come to a verb which really is irregular and you 
mistrust it. Both of you become tired, frustrated, upset. At the end of an 
hour or so the Indian is worn out, his friendship for you has materially 
decreased, and you yourself are glad to quit. 

Hours and days of this, and it's not enough. I have put my finger upon 
the village of Santa Eulalia and said, "Here is the true, the classic Kan- 
hobal from which the other dialects diverge." Then I must sample the 
others; there are at least eight villages which must yield me up fairly com- 
plete word-lists and two from which my material should be as complete 
as from Santa Eulalia. More hours and more days, long horseback trips 
across the mountains to enter strange, suspicious settlements, sleep on the 
dirt floor of the schoolhouse, and persuade the astonished yokelry that it 
is a good idea, a delightful idea, that you should put "The Tongue 1 ' into 
writing. Bad food, a bout of malaria, and the early-morning horror of 
seeing your beloved horse's neck running blood from vampire bats ("Oh, 
but, yes, sefior, everyone knows that here are very troublesome the vam- 
pire bats"), to get the raw material for proving that Jacalteca is a dialect 
of Kanhobal instead of ... 

You bring your hard-won data back to the States and you follow up with 
a sort of detective-quest for obscure publications and old manuscripts 
which may show a couple of words of the language as it was spoken a 
few centuries ago, so that you can get a line on its evolution. With great 
labor you unearth and read the very little that has been written bearing 
upon this particular problem. 

By now the sheer force of effort expended gives your enterprise value in 
your own eyes. And you still have a year's work to put all your data in 
shape, test your conclusions, and demonstrate your proof. 

Yet the real emotional drive goes beyond all this. Suppose I complete my 
work and prove, in fact, that Kanhobal as spoken in Santa Eulalia is a 
language in its own right and the classic tongue from which Jacalteca has 
diverged under alien influences, and that, further, I show just where the 
gradations of speech in the intervening villages fit in. Dear God, what a 
small, dull grain of sand! 

But follow the matter a little farther. Jacalteca being relatively well- 
known (I can, offhand, name four men who have given it some study), 
from it it has been deduced that this whole group of dialects is most closely 
related to the languages spoken south and east of these mountains. If my 
theory is correct, the reverse is true the group belongs to the Northern 
Division of the Mayan Family. This fact, taken along with others regard- 


ing physical appearance, ancient remains, and present culture, leads to a 
new conclusion about the direction from which these tribes came into the 
mountains: a fragment of the ancient history of what was once a great, 
civilized people comes into view. So now my tiny contribution begins to 
be of help to men working in other branches of anthropology than my 
own, particularly to the archaeologists; it begins to help toward an even- 
tual understanding of the whole picture in this area: the important ques- 
tion of, not what these people are to-day, but how they got that way and 
what we can learn from that about all human behavior including our 

Even carrying the line of research as far as this assumes that my results 
have been exploited by men of greater attainments than I. Sticking to the 
linguistic line, an error has been cleared away, an advance has been made 
in our understanding of the layout and interrelationship of the many lan- 
guages making up the Mayan Family. With this we come a step nearer to 
working out the processes by which these languages became different from 
one another and hence to determining the archaic, ancestral roots of the 
whole group. 

So far as we know at present, there are not less than eight completely 
unrelated language families in America north of Panama. This is un- 
reasonable: there are hardly that many families among all the peoples of 
the Old World. Twenty years ago we recognized not eight, but forty. 
Some day perhaps we shall cut the total to four. The understanding of the 
Mayan process is a step toward that day; it is unlikely that Mayan will 
remain an isolated way of speech unconnected with any other. We know 
now that certain tribes in Wyoming speak languages akin to those of 
others in Panama; we have charted the big masses and islands of that 
group of tongues and from the chart begin to see the outlines of great 
movements and crashing historical events in the dim past. If we should 
similarly develop a relationship between Mayan and, let's say, the lan- 
guages of the Mississippi Valley, again we should offer something provoc- 
ative to the archaeologist, the historian, the student of mankind. Some 
day we shall show an unquestionable kinship between some of these 
families and certain languages of the Old World and with it cast a new 
light on the dim subject of the peopling of the Americas, something to 
guide our minds back past the Arctic to dark tribes moving blindly from 
the high plateaus of Asia. 

My petty detail has its place in a long project carried out by many men 
which will serve not only the history of language but the broad scope of 
history itself. It goes farther than that. The humble Pah-Utes of Nevada 
speak a tongue related to that which the subtle Montezuma used, the one 


narrow in scope, evolved only to meet the needs of a primitive people, the 
other sophisticated, a capable instrument for poetry, for an advanced gov- 
ernmental system, and for philosophical speculation. Men's thoughts make 
language and their languages make thought. When the matter of the 
speech of mankind is fully known and laid side by side with all the other 
knowledges, the philosophers, the men who stand at the gathering-together 
point of science, will have the means to make man understand himself 
at last. 

Of course no scientist can be continuously aware of such remote possible 
consequences of his labors; in fact the long goal is so remote that if he 
kept his eyes on it he would become hopelessly discouraged over the half 
inch of progress his own life's work will represent. But it was the vision 
of this which first made him choose his curious career, and it is an emo- 
tional sense of the great structure of scientific knowledge to which his 
little grain will be added which drives him along. 


I spoke of the item of glory, the half dozen colleagues who will appre- 
ciate one's work. To understand that one must first understand the isola- 
tion of research, a factor which has profound effects upon the scientist's 

The most obvious statement of this is in the public attitude and folk- 
literature about "professors." The titles and subjects of Ph.D. theses have 
long been sources of exasperated humor among us; we are all familiar 
with the writer's device which ascribes to a professorial character an in- 
tense interest in some such matter as the development of the molars in 
pre-Aurignacian man or the religious sanctions of the Levirate in north- 
eastern Australia, the writer's intention being that the reader shall say "Oh 
God!", smile slightly, and pigeonhole the character. But what do you sup- 
pose is the effect of the quite natural public attitude behind these devices 
upon the man who is excitedly interested in pre-Aurignacian molars and 
who knows that this is a study of key value in tracing the evolution of 
Homo sapiens? 

Occasionally some line of research is taken up and made clear, even fasci- 
nating, to the general public, as in Zinsser's Rats, Lice and History, or de 
Kruif's rather Sunday-supplement writings. Usually, as in these cases, they 
deal with medicine or some other line of work directly resulting in findings 
of vital interest to the public. Then the ordinary man will consent to under- 
stand, if not the steps of the research itself, at least its importance, will 
grant the excitement, and honor the researcher. When we read Eve Curie's 
great biography of her parents our approach to it is colored by our knowl- 


edge, forty years later, of the importance of their discovery to every one 
of us. It would have been quite possible at the time for a malicious or 
merely ignorant writer to have presented that couple as archetypes of the 
"professor," performing incomprehensible acts of self-immolation in 
pursuit of an astronomically unimportant what's-it. 

Diving to my own experience like a Stuka with a broken wing, I con- 
tinue to take my examples from my rather shallow linguistic studies be- 
cause, in its very nature, the kind of thing a linguist studies is so beauti- 
fully calculated to arouse the "Oh God!" emotion. 

It happened that at the suggestion of my letters I embarked upon an 
ambitious, general comparative study of the whole Mayan Family. The 
farther in I got the farther there was to go and the more absorbed I be- 
came. Puzzle piled upon puzzle to be worked out and the solution used 
for getting after the next one, the beginning of order in chaos, the glimpse 
of understanding at the far end. Memory, reasoning faculties, realism, and 
imagination were all on the stretch; I was discovering the full reach of 
whatever mental powers I had. When I say that I became absorbed I 
mean absorbed; the only way to do such research is to roll in it, become 
soaked in it, live it, breathe it, have your system so thoroughly permeated 
with it that at the half glimpse of a fugitive possibility everything you 
have learned so far and everything you have been holding in suspension 
is in order and ready to prove or disprove that point. You do not only 
think about your subject while the documents are spread before you; 
everyone knows that some of our best reasoning is done when the surface 
of the mind is occupied with something else and the deep machinery of 
the brain is free to work unhampered. 

One day I was getting aboard a trolley car in New Orleans on my way 
to Tulane University. As I stepped up I saw that if it were possible to 
prove that a prefixed s- could change into a prefixed y- a whole series of 
troublesome phenomena would fall into order. The transition must come 
through u- and, thought I with a sudden lift of excitement, there may be 
a breathing associated with u- and that may make the whole thing pos- 
sible. As I paid the conductor I thought that the evidence I needed might 
exist in Totonac and Tarascan, non-Mayan languages with which I was 
not familiar. The possibilities were so tremendous that my heart pounded 
and I was so preoccupied that I nearly went to sit in the Jim Crow sec- 
tion. Speculation was useless until I could reach the University and dig 
out the books, so after a while I calmed myself and settled to my morning 
ration of Popeye, who was then a new discovery too. As a matter of fact, 
the idea was no good, but the incident is a perfect example of the "profes- 
sor mind." 


Of course, i as I stepped on to the car it had dawned upon me that the 
reason my girl's behavior last evening had seemed odd was that she had 
fallen for the Englishman we had met, the incident would not have seemed 
so funny, although the nature of the absorption, subconscious thinking, 
and realization would have been the same in both cases. 

I lived for a month with the letter ^. If we have three words in Quiche, 
one of the major Mayan languages, beginning with ^, in Kanhobal we 
are likely to find that one of these begins with ch. Moving farther west 
and north, in Tzeltal one is likely to begin with ^, one with ch, and the 
one which began with ch in Kanhobal to begin with ts. In Hausteca, at 
the extreme northwest, they begin with ^, ts, and plain s respectively. Why 
don't they all change alike? Which is the original form? Which way do 
these changes run, or from which point do they run both ways? Until 
those questions can be answered we cannot even guess at the form of the 
mother tongue from which these languages diverged, and at that point all 
investigation halts. Are these J(s in Quiche pronounced even faintly 
unlike? I noticed no difference between the two in Kanhobal, but then I 
wasn't listening for it. I wished someone properly equipped would go and 
listen to the Quiche Indians, and wondered if I could talk the University 
into giving me money enough to do so. 

This is enough to give some idea of the nature of my work, and its use- 
lessness for general conversation. My colleagues at Tulane were archae- 
ologists. Shortly after I got up steam they warned me frankly that I had 
to stop trying to tell them about the variability of ^, the history of Puctun 
t y y or any similar matter. If I produced any results that they could apply, I 
could tell them about it; but apart from that I could keep my damned 
sound-shifts and intransitive infixes to myself; I was driving them nuts. 
My other friends on the faculty were a philosopher and two English pro- 
fessors; I was pursuing two girls at the time but had not been drawn to 
either because of intellectual interests in common; my closest friends were 
two painters and a sculptor. The only person I could talk to was myself. 

The cumulative effect of this non-communication was terrific. A strange, 
mute work, a thing crying aloud for discussion, emotional expression, the 
check and reassurance of another's point of view, turned in upon myself 
to boil and fume, throwing upon me the responsibility of being my own 
sole check, my own impersonal, external critic. When finally I came to 
New York on vacation I went to see my Uncle John. He doesn't know 
Indian languages but he is a student of linguistics, and I shall never forget 
the relief, the reveling pleasure, of pouring my work out to him. 

Thus at the vital point of his life-work the scientist is cut off from com- 
munication with his fellow-men. Instead, he has the society of two, six, or 


twenty men and women who are working in his specialty, with whom he 
corresponds, whose letters he receives like a lover, with whom when he 
meets them he wallows in an orgy of talk, in the keen pleasure of conclu- 
sions and findings compared, matched, checked against one another the 
pure joy of being really understood. 

The praise and understanding of those two or six become for him the 
equivalent of public recognition. Around these few close colleagues is the 
larger group of workers in the same general field. They do not share with 
one in the steps of one's research, but they can read the results, tell in a 
general way if they have been soundly reached, and profit by them. To 
them McGarnigle "has shown" that there are traces of an ancient, doli- 
chocephalic strain among the skeletal remains from Pusilha, which is 
something they can use. Largely on the strength of his close colleagues' 
judgment of him, the word gets round that McGarnigle is a sound man. 
You can trust his work. He's the fellow you want to have analyze the 
material if you turn up an interesting bunch of skulls. All told, including 
men in allied fields who use his findings, some fifty scientists praise him; 
before them he has achieved international reputation. He will receive hon- 
ors. It is even remotely possible that he might get a raise in salary. 

McGarnigle disinters himself from a sort of fortress made of boxes full 
of skeletons in the cellar of Podunk University's Hall of Science, and 
emerges into the light of day to attend a Congress. At the Congress he 
delivers a paper entitled Additional Evidence of Dolichocephaly among 
the Eighth Cycle Maya before the Section on Physical Anthropology. In 
the audience are six archaeologists specializing in the Maya field, to whom 
these findings have a special importance, and twelve physical anthropol- 
ogists including Gruenwald of Eastern California, who is the only other 
man working on Maya remains. 

After McGarnigle's paper comes Gruenwald's turn. Three other physi- 
cal anthropologists, engaged in the study of the Greenland Eskimo, the 
Coastal Chinese, and the Pleistocene Man of Lake Mojave respectively, 
come in. They slipped out for a quick one while McGarnigle was speak- 
ing because his Maya work is not particularly useful to them and they can 
read the paper later; what is coming next, with its important bearing on 
method and theory, they would hate to miss. 

Gruenwald is presenting a perfectly horrible algebraic formula and a 
diagram beyond Rube Goldberg's wildest dream, showing A Formula for 
Approximating the Original Indices of Artificially Deformed Crania. 
(These titles are not mere parodies; they are entirely possible.) The archae- 
ologists depart hastily to hear a paper in their own section on Indica- 
tion^ of an Early Quinary System at Uaxactun. The formula is intensely 


exciting to McGarnigle because it was the custom of the ancient Mayas 
to remodel the heads of their children into shapes which they (errone- 
ously) deemed handsomer than nature's. He and Gruenwald have been 
corresponding about this; at one point Gruenwald will speak of his col- 
league's experience in testing the formula; he has been looking forward 
to this moment for months. 

After the day's sessions are over will come something else he has been 
looking forward to. He and Gruenwald, who have not seen each other in 
two years, go out and get drunk together. It is not that they never get 
drunk at home, but that now when in their cups they can be uninhibited, 
they can talk their own, private, treble-esoteric shop. It is an orgy of 


In the course of their drinking it is likely if an archaeologist or two 
from the area joins them it is certain that the talk will veer from femoral 
pilasters' and alveolar prognathism to personal experiences in remote sec- 
tions of the Peten jungle. For in my science and a number of others there 
is yet another frustration. 

We go into the field and there we have interesting experiences. The 
word "adventure" is taboo and "explore" is used very gingerly. But the 
public mind has been so poisoned by the outpourings of bogus explorers 
that it is laden with claptrap about big expeditions, dangers, hardships, 
hostile tribes, the lighting of red flares around the camp to keep the sav- 
ages at bay, and God knows what rot. (I can speak freely about this be- 
cause my own expeditions have been so unambitious and in such easy 
country that I don't come into the subject.) As a matter of fact it is gen- 
erally true that for a scientist on an expedition to have an adventure is 
evidence of a fault in his technique. He is sent out to gather information, 
and he has no business getting into "a brush with the natives." 

The red-flare, into-the-unknown, hardship-and-danger boys, who man- 
age to find a tribe of pink-and-green Indians, a lost city, or the original, 
handpainted descendants of the royal Incas every time they go out, usually 
succeed in so riling the natives and local whites upon whom scientists 
must depend if they are to live in the country as to make work in the 
zones they contaminate difficult for years afterward. The business of their 
adventures and discoveries is sickening. . . . 

These men by training express themselves in factual, "extensional" 
terms, which don't make for good adventure stories. They understand- 
ably lean over backward to avoid sounding even remotely like the frauds, 


the "explorers." And then what they have seen and done lacks validity to 
them if it cannot be told in relation to the purpose and dominant emotion 
which sent them there. McGarnigle went among the independent Indians 
of Icaiche because he had heard of a skull kept in one of their temples 
which, from a crude description, seemed to have certain important char- 
acteristics. All his risks and his maneuverings v/ith those tough, explosive 
Indians centered around the problem of gaining access to that skull. When 
he tries to tell an attractive girl about his experiences he not only under- 
states, but can't keep from stressing the significance of a skull with a 
healed, clover-leaf trepan. The girl gladly leaves him for the nearest 
broker. . . . 

It is too bad both for the scientists and the public that they are so cut 
off from each other. The world needs now not the mere knowledges of 
science, but the way of thought and the discipline. It is the essence of 
what Hitler has set out to destroy; against it he has waged total war within 
his own domain. It is more than skepticism, the weighing of evidence 
more even than the love of truth. It is the devotion of oneself to an end 
which is far more important than the individual, the certainty that the 
end is absolutely good, not only for oneself but for all mankind, and the 
character to set personal advantage, comfort, and glory aside in the de- 
voted effort to make even a little progress toward it. 

Turtle Eggs for Agassiz 


-"* few books are written. With every human being a possible book, and 
with many a human being capable of becoming more books than the 
world could contain, is it not amazing that the books of men are so few? 
And so stupid! 

I took down, recently, from the shelves of a great public library, the 
four volumes of Agassiz's Contributions to the Natural History of the 
United States. I doubt if anybody but the charwoman, with her duster, 
had touched those volumes for twenty-five years. They are an excessively 
learned, a monumental, an epoch-making work, the fruit of vast and 
heroic labors, with colored plates on stone, showing the turtles of the 
United States, and their embryology. The work was published more than 
half a century ago (by subscription) ; but it looked old beyond its years 
massive, heavy, weathered, as if dug from the rocks. It was difficult to feel 
that Agassiz could have written it could have built it, grown it, for the 
laminated pile had required for its growth the patience and painstaking 
care of a process of nature, as if it were a kind of printed coral reef. Agas- 
siz do this? The big, human, magnetic man at work upon these pages of 
capital letters, Roman figures, brackets, and parentheses in explanation of 
the pages of diagrams and plates! I turned away with a sigh from the 
weary learning, to read the preface. 

When a great man writes a great book he usually flings a preface after 
it, and thereby saves it, sometimes, from oblivion. Whether so or not, the 
best things in most books are their prefaces. It was not, however, the qual- 
ity of the preface to these great volumes that interested me, but rather the 
wicked waste of durable book material that went to its making. Reading 
down through the catalogue of human names and of thanks for help re- 
ceived, I came to a sentence beginning: 

"In New England I have myself collected largely; but I have also re- 



ceived valuable contributions from the late Rev. Zadoc Thompson of Bur- 
lington . . . from Mr. D. Henry Thoreau of Concord . . . and from Mr. 
J. W. P. Jenks of Middleboro." And then it hastens on with the thanks in 
order to get to the turtles, as if turtles were the one and only thing of real 
importance in all the world. 

Turtles no doubt are important, extremely important, embryologically, 
as part of our genealogical tree; but they are away down among the roots 
of the tree as compared with the late Rev. Zadoc Thompson of Burling- 
ton. I happen to know nothing about the Rev. Zadoc, but to me he looks 
very interesting. Indeed any reverend gentleman of his name and day 
who would catch turtles for Agassiz must have been interesting. And as 
for Henry Thoreau, we know he was interesting. The rarest wood turtle 
in the United States was not so rare a specimen as this gentleman of Wai- 
den Woods and Concord. We are glad even for this line in the preface 
about him; glad to know that he tried, in this untranscendental way, to 
serve his day and generation. If Agassiz had only put a chapter in his 
turtle book about it! But this is the material he wasted, this and more of 
the same human sort, for the Mr. "J en ks of Middleboro" (at the end of the 
quotation) was, years later, an old college professor of mine, who told me 
some of the particulars of his turtle contributions, particulars which Agas- 
siz should have found a place for in his big book. The preface says merely 
that this gentleman sent turtles to Cambridge by the thousands brief 
and scanty recognition. For that is not the only thing this gentleman did. 
On one occasion he sent, not turtles, but turtle eggs to Cambridge 
brought them, I should say; and all there is to show for it, so far as I 
could discover, is a sectional drawing of a bit of the mesoblastic layer of 
one of the eggs! 

Of course, Agassiz wanted to make that mesoblastic drawing, or some 
other equally important drawing, and had to have the fresh turtle egg to 
draw it from. He had to have it, and he got it. A great man, when he 
wants a certain turtle egg, at a certain time, always gets it, for he gets 
someone else to get it. I am glad he got it. But what makes me sad and im- 
patient is that he did not think it worth while to tell about the getting of 
it, and so made merely a learned turtle book of what might have been an 
exceedingly interesting human book. 

It would seem, naturally, that there could be nothing unusual or inter- 
esting about the getting of turtle eggs when you want them. Nothing at 
all, if you should chance to want the eggs as you chance to find them. So 
with anything else good copper stock, for instance, if you should chance 
to want it, and should chance to be along when they chance to be giving 
it away. But if you want copper stock, say of C & H quality, when you 


want it, and are bound to have it, then you must command more than a 
college professor's salary. And likewise, precisely, when it is turtle eggs 
that you are bound to have. 

Agassiz wanted those turtle eggs when he wanted them not a minute 
over three hours from the minute they were laid. Yet even that does not 
seem exacting, hardly more difficult than the getting of hen eggs only 
three hours old. Just so, provided the professor could have had his private 
turtle coop in Harvard Yard; and provided he could have made his turtles 
lay. But turtles will not respond, like hens, to meat scraps and the warm 
mash. The professor's problem was not to get from a mud turtle's nest in 
the back yard to the table in the laboratory; but to get from the laboratory 
in Cambridge to some pond when the turtles were laying, and back to 
the laboratory within the limited time. And this, in the days of Darius 
Green, might have called for nice and discriminating work as it did. 

Agassiz had been engaged for a long time upon his Contributions. He 
had brought the great work nearly to a finish. It was, indeed, finished but 
for one small yet very important bit of observation: he had carried the 
turtle egg through every stage of its development with the single excep- 
tion of one the very earliest that stage of first cleavages, when the cell 
begins to segment, immediately upon its being laid. That beginning stage 
had brought the Contributions to a halt. To get eggs that were fresh 
enough to show the incubation at this period had been impossible. 

There were several ways that Agassiz might have proceeded: he might 
have got a leave of absence for the spring term, taken his laboratory to 
some pond inhabited by turtles, and there camped until he should catch 
the reptile digging out her nest. But there were difficulties in all of that 
as those who are college professors and naturalists know. As this was 
quite out of the question, he did the easiest thing asked Mr. "Jenks of 
Middleboro" to get him the eggs. Mr. Jenks got them. Agassiz knew all 
about his getting of them; and I say the strange and irritating thing is 
that Agassiz did not think it worth while to tell us about it, a least in the 
preface to his monumental work. 

It was many years later that Mr. Jenks, then a gray-haired college pro- 
fessor, told me how he got those eggs to Agassiz. 

"I was principal of an academy, during my younger years," he began, 
"and was busy one day with my classes, when a large man suddenly filled 
the doorway of the room, smiled to the four corners of the room, and 
called out with a big, quick voice that he was Professor Agassiz. 

"Of course he was. I knew it, even before he had had time to shout it 
to me across the room. 

"Would I get him some turtle eggs? he called. Yes, I would. And would 


I get them to Cambridge within three hours from the time they were laid? 
Yes, I would. And I did. And it was worth the doing. But I did it only 

"When I promised Agassiz those eggs I knew where I was going to 
get them. I had got turt le eggs there before at a particular patch of sandy 
shore along a pond, a few miles distant from the academy. 

"Three hours was the limit. From the railroad station to Boston was 
thirty-five miles; from tiie pond to the station was perhaps three or four 
miles; from Boston to Cambridge we called about three miles. Forty miles 
in round numbers! We figured it all out before he returned, and got the 
trip down to two hours record time: driving from the pond to the sta- 
tion; from the station by express train to Boston; from Boston by cab to 
Cambridge. This left an easy hour for accidents and delays. 

"Cab and car and carriage we reckoned into our time-table; but what 
we didn't figure on was the turtle." And he paused abruptly. 

"Young man," he went on, his shaggy brows and spectacles hardly 
hiding the twinkle in the eyes that were bent severely upon me, "young 
man, when you go after turtle eggs, take into account the turtle. No! no! 
That's bad advice. Youth never reckons on the turtle and youth seldom 
ought to. Only old age does that; and old age would never have got those 
turtle eggs to Agassiz. 

"It was in the early spring that Agassiz came to the academy, long 
before there was any likelihood of the turtles laying. But I was eager for 
the quest, and so fearful of failure that I started out to watch at the pond 
fully two weeks ahead of the time that the turtles might be expected to 
lay. I remember the date clearly: it was May 14. 

"A little before dawn along near three o'clock I would drive over to 
the pond, hitch my horse near by, settle myself quietly among some thick 
cedars close to the sandy shore, and there I would wait, my kettle of sand 
ready, my eye covering the whole sleeping pond. Here among the cedars I 
would eat my breakfast, and then get back in good season to open the 
academy for the morning session. 

"And so the watch began. 

"I soon came to know individually the dozen or more turtles that kept 
to my side of the pond. Shortly after the cold mist would lift and melt 
away they would stick up their heads through the quiet water; and as the 
sun slanted down over the ragged rim of tree tops the slow things would 
float into the warm, lighted spots, or crawl out and doze comfortably on 
the hummocks and snags, 

"What fragrant mornings those were! How fresh and new and un- 
breathed! The pond odors, the woods odors, the odors of the ploughed 


fields of water lily, and wild grape, and the dew-laid soil! I can taste 
them yet, and hear them yet the still, large sounds of the waking day 
the pickerel breaking the quiet with his swirl; the kingfisher dropping 
anchor; the stir of feet and wings among the trees. And then the thought 
of the great book being held up for me! Those were rare mornings! 

"But there began to be a good many of them, for the turtles showed no 
desire to lay. They sprawled in the sun, and never one came out upon the 
sand as if she intended to help on the great professor's book. The em- 
bryology of her eggs was of small concern to her; her contribution to the 
Natural History of the United States could wait. 

"And it did wait. I began my watch on the fourteenth of May; June first 
found me still among the cedars, still waiting, as I had waited every morn- 
ing, Sundays and rainy days alike. June first saw a perfect morning, but 
every turtle slid out upon her log, as if egg laying might be a matter strictly 
of next year. 

"I began to grow uneasy not impatient yet, for a naturalist learns his 
lesson of patience early, and for all his years; but I began to fear lest, by 
some subtile sense, my presence might somehow be known to the crea- 
tures; that they might have gone to some other place to lay, while I was 
away at the schoolroom. 

"I watched on to the end of the first week, on to the end of the second 
week in June, seeing the mists rise and vanish every morning, and along 
with them vanish, more and more, the poetry of my early morning vigil. 
Poetry and rheumatism cannot long dwell together in the same clump of 
cedars, and I had begun to feel the rheumatism. A month of morning 
mists wrapping me around had at last soaked through to my bones. But 
Agassiz was waiting, and the world was waiting, for those turtle eggs; 
and I would wait. It was all I could do, for there is no use bringing a 
china nest egg to a turtle; she is not open to any such delicate suggestion. 

"Then came a mid-June Sunday morning, with dawn breaking a little 
after three: a warm, wide-awake dawn, with the level mist lifted from the 
level surface of the pond a full hour higher than I had seen it any morning 

"This was the day: I knew it. I have heard persons say that they can 
hear the grass grow; that they know by some extra sense when danger is 
nigh. That we have these extra senses I fully believe, and I believe they can 
be sharpened by cultivation. For a month I had been watching, brooding 
over this pond, and now I knew. I felt a stirring of the pulse of things 
that the cold-hearted turtles could no more escape than could the clods 
and I. 

"Leaving my horse unhitched, as if he too understood, I slipped eagerly 


into my covert for a look at the pond. As I did so, a large pickerel 
ploughed a furrow out through the spatter-docks, and in his wake rose 
the head of an enormous turtle. Swinging slowly around, the creature 
headed straight for the shore, and without a pause scrambled out on the 

"She was about the size of a big scoop shovel; but that was not what 
excited me, so much as her manner, and the gait at which she moved; for 
there was method in it, and fixed purpose. On she came, shuffling over the 
sand toward the higher open fields, with a hurried, determined seesaw 
that was taking her somewhere in particular, and that was bound to get 
her there on time. 

"I held my breath. Had she been a dinosaurian making Mesozoic foot- 
prints, I could not have been more fearful. For footprints in the Mesozoic 
mud, or in the sands of time, were as nothing to me when compared with 
fresh turtle eggs in the sands of this pond. 

"But over the strip of sand, without a stop, she paddled, and up a 
narrow cow path into the high grass along a fence. Then up the narrow 
cow path, on all fours, just like another turtle, I paddled, and into the 
high wet grass along the fence. 

"I kept well within sound of her, for she moved recklessly, leaving a 
trail of flattened grass a foot and a half wide. I wanted to stand up, and I 
don't believe I could have turned her back with a rail, but I was afraid 
if she saw me that she might return indefinitely to the pond; so on I 
went, flat to the ground, squeezing through the lower rails of the fence, 
as if the field beyond were a melon patch. It was nothing of the kind, only 
a wild, uncomfortable pasture, full of dewberry vines, and very dis- 
couraging. They were excessively wet vines and briery. I pulled my coat 
sleeves as far over my fists as I could get them, and, with the tin pail of 
sand swinging from between my teeth to avoid noise, I stumped fiercely, 
but silently, on after the turtle. 

"She was laying her course, I thought, straight down the length of this 
dreadful pasture, when, not far from the fence, she suddenly hove to, 
warped herself short about, and came back, barely clearing me, at a clip 
that was thrilling. I warped about, too, and in her wake bore down 
across the corner of the pasture, across the powdery public road, and on to 
a fence along a field of young corn. 

"I was somewhat wet by this time, but not so wet as I had been before, 
wallowing through the deep dry dust of the road. Hurrying up behind a 
large tree by the fence, I peered down the corn rows and saw the turtle 
stop, and begin to paw about in the loose soft soil. She was going to lay! 

"I held on to the tree and watched, as she tried this place, and that place, 


and the other place the eternally feminine! But the place, evidently, was 
hard to find. What could a female turtle do with a whole field of possible 
nests to choose from? Then at last she found it, and, whirling about, she 
backed quickly at it, and, tail first, began to bury herself before my staring 

"Those were not the supreme moments of my life; perhaps those 
moments came later that day; but those certainly were among the slowest, 
most dreadfully mixed of moments that I ever experienced. They were 
hours long. There she was, her shell just showing, like some old hulk in 
the sand alongshore. And how long would she stay there? And how 
should I know if she had laid an egg? 

"I could still wait. And so I waited, when, over the freshly awakened 
fields, floated four mellow strokes from the distant town clock. 

"Four o'clock! Why, there was no train until seven 1 No train for three 
hours! The eggs would spoil! Then with a rush it came over me that this 
was Sunday morning, and there was no regular seven o'clock train none 
till after nine. 

"I think I should have fainted had not the turtle just then begun 
crawling off. I was weak and dizzy; but there, there in the sand, were the 
eggs! And Agassiz! And the great book! And I cleared the fence, and the 
forty miles that lay between me and Cambridge, at a single jump. He 
should have them, trains or no. Those eggs should go to Agassiz by seven 
o'clock, if I had to gallop every mile of the way. Forty miles! Any horse 
could cover it in three hours, if he had to; and, upsetting the astonished 
turtle, I scooped out her round white eggs. 

"On a bed of sand in the bottom of the pail I laid them, with what 
care my trembling fingers allowed; filled in between them with more 
sand; so with another layer to the rim; and, covering all smoothly with 
more sand, I ran back for my horse. 

"That horse knew, as well as I, that the turtle had laid, and that he 
was to get those eggs to Agassiz. He turned out of that field into the road 
on two wheels, a thing he had not done for twenty years, doubling me up 
before the dashboard, the pail of eggs miraculously lodged between my 

"I let him out. If only he could keep this pace all the way to Cambridge! 
Or even halfway there; and I should have time to finish the trip on foot. 
I shouted him on, holding to the dasher with one hand, the pail of eggs 
with the other, not daring to get off my knees, though the bang on them, 
as we pounded down the wood road, was terrific. But nothing must 
happen to the eggs; they must not be jarred, or even turned over in the 
sand before they come tc? Agassiz. 


"In order to get out on the pike it was necessary to drive back away 
from Boston toward the town. We had nearly covered the distance, and 
were rounding a turn from the woods into the open fields, when, ahead 
of me, at the station it seemed, I heard the quick sharp whistle of a loco- 

"What did it mean? Then followed the puff, puff f puff of a starting 
train. But what train? Which way going? And, jumping to my feet for a 
longer view, I pulled into a side road that paralleled the track, and headed 
hard for the station. 

"We reeled along. The station was still out of sight, but from behind the 
bushes that shut it from view rose the smoke of a moving engine. It was 
perhaps a mile away, but we were approaching, head-on, and, topping a 
little hill, I swept down upon a freight train, the black smoke pouring 
from the stack, as the mighty creature pulled itself together for its swift 
run down the rails. 

"My horse was on the gallop, going with the track, and straight toward 
the coming train. The sight of it almost maddened me the bare thought 
of it, on the road to Boston! On I went; on it came, a half a quarter of a 
mile between us, when suddenly my road shot out along an unfenced field 
with only a level stretch of sod between me and the engine. 

"With a pull that lifted the horse from his feet, I swung him into the 
field and sent him straight as an arrow for the track. That train should 
carry me and my eggs to Boston! 

"The engineer pulled the rope. He saw me standing up in the rig, saw 
my hat blow off, saw me wave my arms, saw the tin pail swing in my 
teeth, and he jerked out a succession of sharp halts! But it was he who 
should halt, not I; and on we went, the horse with a flounder landing the 
carriage on top of the track. 

"The train was already grinding to a stop; but before it was near a 
stand-still I had backed off the track, jumped out, and, running down the 
rails with the astonished engineers gaping at me, had swung aboard the 

"They offered no resistance; they hadn't had time. Nor did they have 
the disposition, for I looked strange, not to say dangerous. Hatless, dew- 
soaked, smeared with yellow mud, and holding, as if it were a baby or a 
bomb, a little tin pail of sand. 

" 'Crazy,' the fireman muttered, looking to the engineer for his cue. 

"I had been crazy, perhaps, but I was not crazy now. 

"'Throw her wide open,' I commanded. 'Wide open! These are fresh 
turtle eggs for Professor Agassiz of Cambridge. He must have them before 


"Then they knew I was crazy, and, evidently thinking it best to humor 
me, threw the throttle wide open, and away we went. 

"I kissed my hand to the horse, grazing unconcernedly in the open field, 
and gave a smile to my crew. That was all I could give them, and hold 
myself and the eggs together. But the smile was enough. And they smiled 
through their smut at me, though one of them held fast to his shovel, 
while the other kept his hand upon a big ugly wrench. Neither of them 
spoke to me, but above the roar of the swaying engine I caught enough of 
their broken talk to understand that they were driving under a full head of 
steam, with the intention of handing me over to the Boston police, as 
perhaps the easiest way of disposing of me. 

"I was only afraid that they would try it at the next station. But that 
station whizzed past without a bit of slack, and the next, and the next; 
when it came over me that this was the through freight, which should 
have passed in the night, and was making up lost time. 

"Only the fear of the shovel and the wrench kept me from shaking 
hands with both men at this discovery. But I beamed at them; and they at 
me. I was enjoying it. The unwonted jar beneath my feet was wrinkling 
my diaphragm with spasms of delight. And the fireman beamed at the 
engineer, with a look that said, 'See the lunatic grin; he likes it!' 

"He did like it. How the iron wheels sang to me as they took the rails! 
How the rushing wind in my ears sang to me! From my stand on the fire- 
man's side of the cab I could catch a glimpse of the track just ahead of the 
engine, where the ties seemed to leap into the throat of the mile-devouring 
monster. The joy of it! Of seeing space swallowed by the mile! 

"I shifted the eggs from hand to hand and thought of my horse, of 
Agassiz, of the great book, of my great luck, luck, luck, until the 
multitudinous tongues of the thundering train were all chiming 'luck! 
luck! luck!' They knew! They understood! This beast of fire and tireless 
wheels was doing its very best to get the eggs to Agassiz! 

"We swung out past the Blue Hills, and yonder flashed the morning 
sun from the towering dome of the State House. I might have leaped from 
the cab and run the rest of the way on foot, had I not caught the eye of 
the engineer watching me narrowly. I was not in Boston yet, nor in 
Cambridge either. I was an escaped lunatic, who had held up a train, and 
forced it to carry me to Boston. 

"Perhaps I had overdone my lunacy business. Suppose these two men 
should take it into their heads to turn me over to the police, whether I 
would or no? I could never explain the case in time to get the eggs to 
Agassiz. I looked at my watch. There were still a few minutes left, in 
which I might explain to these men, who, all at once, had become my 


captors. But it was too late. Nothing could avail against my actions, my 
appearance, and my little pail of sand. 

"I had not thought of my appearance before. Here I was, face and 
clothes caked with yellow mud, my hair wild and matted, my hat gone, 
and in my full-grown hands a tiny tin pail of sand, as if I had been 
digging all night with a tiny tin shovel on the shore! And thus to appear 
in the decent streets of Boston of a Sunday morning! 

"I began to feel like a hunted criminal. The situation was serious, or 
might be, and rather desperately funny at its best. I must in some way 
have shown my new fears, for both men watched me more sharply. 

"Suddenly, as we were nearing the outer freight yard, the train slowed 
down and came to a stop. I was ready to jump, but I had no chance. They 
had nothing to do, apparently, but to guard me. I looked at my watch 
again. What time we had made! It was only six o'clock, with a whole hour 
to get to Cambridge. 

"But I didn't like this delay. Five minutes ten went by. 

" 'Gentlemen,' I began, but was cut short by an express train coming 
past. We were moving again, on into a siding; on on to the main 
track; and on with a bump and a crash and a succession of crashes, run- 
ning the length of the train; on at a turtle's pace, but on, when the fireman, 
quickly jumping for the bell rope, left the way to the step free, and the 
chance had come! 

"I never touched the step, but landed in the soft sand at the side of the 
track, and made a line for the yard fence. 

"There was no hue or cry. I glanced over my shoulder to see if they were 
after me. Evidently their hands were full, and they didn't know I had 

"But I had gone; and was ready to drop over the high board fence, 
when it occurred to me that I might drop into a policeman's arms. 
Hanging my pail in a splint on top of a post, I peered cautiously over a 
very wise thing to do before you jump a high board fence. There, crossing 
the open square toward the station, was a big, burly fellow with a club 
looking for me. 

"I flattened for a moment, when someone in the yard yelled at me. I 
preferred the policeman, and, grabbing my pail, I slid over to the street. 
The policeman moved on past the corner of the station out of sight. The 
square was free, and yonder stood a cab! 

"Time was flying now. Here was the last lap. The cabman saw me 
coming, and squared away. I waved a paper dollar at him, but he only 
stared the more. A dollar can cover a good deal, but I was too much for 


one dollar. I pulled out another, thrust them both at him, and dodged 
into the cab, calling, 'Cambridge!' 

"He would have taken me straight to the police station had I not said, 
'Harvard College. Professor Agassiz's house! I've got eggs for Agassiz'; 
and pushed another dollar up at him through the hole. 

"It was nearly half past six. 

" 'Let him go!' I ordered. "Here's another dollar if you make Agassiz's 
house in twenty minutes. Let him out; never mind the police!' 

"He evidently knew the police, or there were none around at that time 
on a Sunday morning. We went down the sleeping streets as I had gone 
down the wood roads from the pond two hours before, but with the rattle 
and crash now of a fire brigade. Whirling a corner into Cambridge Street, 
we took the bridge at a gallop, the driver shouting out something in 
Hibernian to a pair of waving arms and a belt and brass buttons. 

"Across the bridge with a rattle and jolt that put the eggs in jeopardy, 
and on over the cobblestones, we went. Half standing, to lessen the jar, I 
held the pail in one hand and held myself in the other, not daring to let 
go even to look at my watch. 

"But I was afraid to look at the watch. I was afraid to see how near to 
seven o'clock it might be. The sweat was dropping from my nose, so close 
was I running to the limit of my time. 

"Suddenly there was a lurch, and I dived forward, ramming my head 
into the front of the cab, coming up with a rebound that landed me 
across the small of my back on the seat, and sent half of my pail of eggs 
helter-skelter over the floor. 

"We had stopped. Here was Agassiz's house; and without taking time 
to pick up the scattered eggs I tumbled out, and pounded at the door. 

"No one was astir in the house. But I would stir them. And I did. Right 
in the midst of the racket the door opened. It was the maid. 

"'Agassiz,' I gasped, 'I want Professor Agassiz, quick!' And I pushed 
by her into the hall. 

" 'Go 'way, sir. I'll call the police. Professor Agassiz is in bed. Go 'way, 

" 'Call him Agassiz instantly, or I'll call him myself.' 

"But I didn't; for just then a door overhead was flung open, a great 
white-robed figure appeared on the dim landing above, and a quick loud 
voice called excitedly: 

" 'Let him in! Let him inl I know him. He has my turtle eggs!' 

"And the apparition, slipperless, and clad in anything but an academic 
gown, came sailing down the stairs, 


"The maid fled. The great man, his arms extended, laid hold of me with 
both hands, and, dragging me and my precious pail into his study, with a 
swift, clean stroke laid open one of the eggs, as the watch in my trembling 
hands ticked its way to seven as if nothing unusual were happening to 
the history of the world." 

"You were in time, then?" I said. 

"To the tick. There stands my copy of the great book. I am proud of the 
humble part I had in it." 


The Aims and Methods of Science 


-^ knowledge argument and experiment. Argument allows us to 
draw conclusions, and may cause us to admit the conclusion; but it 
gives no proof, nor does it remove doubt, and cause the mind to rest 
in the conscious possession of truth, unless the truth is discovered by 
way of experience, e.g. if any man who had never seen fire were to 
prove by satisfactory argument that fire burns and destroys things, the 
hearer's mind would not rest satisfied, nor would he avoid fire; until by 
putting his hand or some combustible thing into it, he proved by actual 
experiment what the argument laid down; but after the experiment has 
been made, his mind receives certainty and rests in the possession of 
truth which could not be given by argument but only by experience. 
And this is the case even in mathematics, where there is the strongest 
demonstration. For let anyone have the clearest demonstration about an 
equilateral triangle without experience of it, his mind will never lay 


hold of the problem until he has actually before him the intersecting 
circles and the lines drawn from the point of section to the extremities 
of a straight line. 





I am glad to see you before me, a flourishing band of young people 
who have chosen applied science as a profession. 

I could sing a hymn of praise with the refrain of the splendid progress 
in applied science that we have already made, and the enormous further 
progress that you will bring about. We are indeed in the era and also 
in the native land of applied science. 

But it lies far from my thought to speak in this way. Much more, I am 
reminded in this connection of the young man who had married a not 
very attractive wife and was asked whether or not he was happy. He 
answered thus: "If I wished to speak the truth, then I would have to 

So it is with me. Just consider a quite uncivilized Indian, whether his 
experience is less rich and happy than that of the average civilized 
man. I hardly think so. There lies a deep meaning in the fact that the 
children of all civilized countries are so fond of playing "Indians." 

Why does this magnificent applied science, which saves work and 
makes life easier, bring us so little happiness? The simple answer 
runs because we have not yet learned to make a sensible use of it. 

In war, it serves that we may poison and mutilate each other. In 
peace it has made our lives hurried and uncertain. Instead of freeing us 
in great measure from spiritually exhausting labor, it has made men into 
slaves of machinery, who for the most part complete their monotonous 
long day's work with disgust, and must continually tremble for their 
poor rations. 

You will be thinking that the old man sings an ugly song. I do it, how- 
ever, with a good purpose, in order to point out a consequence. 


It is not enough that you should understand about applied science 
in order that your work may increase man's blessings. Concern for man 
himself and his fate must always form the chief interest of all technical 
endeavors, concern for the great unsolved problems of the organization 
cf labor and the distribution of goods in order that the creations of our 
mind shall be a blessing and not a curse to mankind. Never forget this 
in the midst of your diagrams and equations. 


From Stars and Atoms 

themselves wings. Daedalus flew safely through the middle air and 
was duly honored on his landing. Icarus soared upwards to the sun till 
the wax melted which bound his wings and his flight ended in fiasco. 
In weighing their achievements, there is something to be said for 
Icarus. The classical authorities tell us that he was only "doing a stunt," 
but I prefer to think of him as the man who brought to light a serious 
constructional defect in the flying machines of his day. So, too, in science, 
cautious Daedalus will apply his theories where he feels confident they 
will safely go; but by his excesses of caution their hidden weaknesses 
remain undiscovered. Icarus will strain his theories to the breaking 
point till the weak points gape. For the mere adventure? Perhaps partly; 
that is human nature. But if he is destined not yet to reach the sun and 
solve finally the riddle of its constitution we may hope at least to 
learn from his journey some hints to build a better machine. 







my country? First of all, sequence, consequence and again con- 
sequence. In gaining knowledge you must accustom yourself to the 
strictest sequence. You must be familiar with the very groundwork of 
science before you try to climb the heights. Never start on the "next" 
before you have mastered the "previous." Do not try to conceal the 
shortcomings of your knowledge by guesses and hypotheses. Accustom 
yourself to the roughest and simplest scientific tools. Perfect as the wing 
of a bird may be, it will never enable the bird to fly if unsupported by 
the air. Facts are the air of science. Without them the man of science 
can never rise. Without them your theories are vain surmises. But while 
you are studying, observing, experimenting, do not remain content with 
the surface of things. Do not become a mere recorder of facts, but try 
to penetrate the mystery of their origin. Seek obstinately for the laws that 
govern them. And thenmodesty. Never think you know all. Though 
others may flatter you, retain the courage to say, "I am ignorant." Never 
be proud. And lastly, science must be your passion. Remember that science 
claims a man's whole life. Had he two lives they would not suuice. 
Science demands an undivided allegiance from its followers. Li your 
work and in your research there must always be passion. 


just as the scientist's objective search for truth will outlive all the 
regimented thinking of totalitarianism. Temporarily eclipsed, the proud 


names of Paris, Strasbourg, Prague, Louvain, Warsaw, Leyden, as well 
as Heidelberg and Leipsic and Berlin, will once again stand for the 
quest for truth; once again will they be centers of candid and fearless 
thinkinghomes of the untrammeled and unafraid, where there is liberty 
to learn, opportunity to teach and power to understand. 

The task which faces all institutions concerned with the advance 
of knowledge is not only to keep this faith alive but to make certain, 
as far as they can, that the streams of culture and learning, wherever 
they may be located or however feebly they may now flow, shall not 
be blocked. . . . 

... If we are to have a durable peace after the war, if out of the 
Wreckage of the present, a new kind of cooperative life is to be built 
on a global scale, the part that science and advancing knowledge will 
play must not be overlooked. For although wars arid economic rivalries 
may for longer or shorter periods isolate nations and split them up into 
separate units, the process is never complete because the intellectual 
life of the world, as far as science and learning are concerned, is definitely 
internationalized, and whether we wish it or not an indelible pattern 
of unity has been woven into the society of mankind. 

There is not an area of activity in which this cannot be illustrated. An 
American soldier, wounded on a battlefield in the Far East, owes his life 
to the Japanese scientist, Kitasato, who isolated the bacillus of tetanus. 
A Russian soldier, saved by a blood transfusion, is indebted to Land- 
steiner, an Austrian. A German soldier is shielded from typhoid fever 
with the help of a Russian, MetchnikofJ. A Dutch marine in the East 
Indies is protected from malaria because of the experiments of an 
Italian, Grassi; while a British aviator in North Africa escapes death 
from surgical infection because a Frenchman, Pasteur, and a German, 
Koch, elaborated a new technique. 

In peace, as in war, we are all of us the beneficiaries of contributions 
to knowledge made by every nation in the world. Our children are 
guarded from diphtheria by what a Japanese and a German did, they 
are protected from smallpox by an Englishman's work; they are saved 
from rabies because of a Frenchman; they are cured of pellagra through 
the researches of an Austrian. From birth to death, they are surrounded 
by an invisible host the spirits of men who never thought in terms of 
flags or boundary lines and who never served a lesser loyalty than the 
welfare of mankind. The best that every individual or group has 
produced anywhere in the world has always been available to serve the 
race of men, regardless of nation or color. 

What is true of the medical sciences is true of the other sciences. 


Whether it is mathematics or chemistry, whether it is bridges or auto- 
mobiles or a new device for making cotton cloth or a cyclotron for 
studying atomic structure, ideas cannot be hedged in behind geographical 
barriers. Thought cannot be nationalized. The fundamental unity of 
civilization is the unity of its intellectual life. 

There is a real sense, therefore, in which the things that divide us are 
trivial as compared with the things that unite us. The foundations of a 
cooperative world have already been laid. It is not as if we were starting 
from the beginning. For at least three hundred years, the process has 
been at work, until today the cornerstones of society are the common 
interests that relate to the welfare of all men everywhere. 

In brief, the age of distinct human societies, indifferent to the fate of 
one another, has passed forever; and the great task that will confront 
us after the war is to develop for the community of nations new areas and 
techniques of cooperative action which will fit the facts of our twentieth 
century interdependence. We need rallying points of unity, centers around 
which men of different cultures and faiths can combine, defined fields of 
need, or goals of effort, in which by pooling its brains and resources, the 
human race can add to its own well-being. Only as we begin to build, 
brick by brick, in these areas of common interest where cooperation is 
possible and the results are of benefit to all, can we erect the ultimate 
structure of a united society. 

A score of inviting areas for this kind of cooperation deserve explo- 
ration. Means must be found by which the potential abundance of the 
world can be translated into a more equitable standard of living. Mini- 
mum standards of food, clothing and shelter should be established. The 
new science of nutrition, slowly coming to maturity, should be expanded 
on a world-wide scale. The science of agriculture needs development, 
not only in our own climate but particularly in the tropic and sub- 
tropic zones. With all their brilliant achievements, the medical sciences 
are in their infancy. Public health stands at the threshold of new 
possibilities. Physics and chemistry have scarcely started their contri- 
butions to the happiness and comfort of human living. Economics and 
political science are only now beginning to tell us in more confident 
tones how to make this world a home to live in instead of a place to 
fight and freeze and starve in. 






ago, Nicholas Copernicus received on his death bed the first copy of his im- 
mortal book, De Revolutionibus Orbium Coelestium (Concerning the Revo- 
lutions of the Heavenly Bodies), in which he expressed his belief that the 
earth moves around the sun. A few hours later he closed his eyes on a 
medieval world that still believed in Ptolemy's geocentric universe. 

Sixty-seven years later, in 1610, Galileo Galilei watched four small bodies 
which appeared in the field of his telescope. Night after night he observed 
them as they moved around the planet Jupiter. Here was a miniature solar 
system similar to our own. Here was proof of the Copernican theory. Thus, 
one of the greatest revolutions in the history of the human race took place. 
Man was no longer the center of the world; he had assumed a subordinate 
place in a larger universe. 

In the following pages this story of Copernicus and Galileo is told in their 
own words. As we read, some of the excitement and wonder which they 
must have felt comes to us across the centuries. 

Since that day, our knowledge of astronomy has greatly increased. We 
know more about the planets; much more about the composition and even 
the internal constitution of the stars; and we have discovered realms far be- 
yond the range of Galileo's little telescope. This Orderly Universe extends 
from OUT familiar satellite, the moon, to those exterior galaxies which are 
visible only in the largest telescopes. To tell us about it, we chose Forest Ray 
Moulton, who with T. C. Chamberlin is responsible for the modern theory 
that the solar system was formed by the passage of a star near our own sun. 
His description is an astronomical education in brief a bird's-eye view ot 
modern astronomy. 



As man loolcs at the planets and shrinks in size before those distant gal- 
axies, it is natural that he should ask Is There Life on Other Worlds? As 
Sir James Jeans explains, science has its answer, based on facts of atmosphere, 
temperature and mathematical ca/culation. 

Life as we know it probably does not exist elsewhere in the solar system. It 
may appear somewhere in our galaxy, or in some other galaxy outside the 
Milky Way. We do not know, although we know much about these ex- 
terior systems. In the field of external galaxies numerous recent develop- 
ments have taken place. In The Milky Way and Beyond, Sir Arthur Edding- 
ton, who is responsible for many of these developments, tells about them and 
explains why he believes the universe is expanding. It is a fascinating hypoth- 
esis, though there is disagreement among astronomers as to its correctness. 
When the 2OO-inch telescope is finished, the problem may be solved. 


From outer space to A Young Man Looking at Rocks is a long jump to 
more familiar ground. It is easier to contemplate the sculptured heart of a 
fossil than the arms of a spiral nebula. Yet for that very reason, we are apt 
to take the "commonest things" for granted. We forget that rocks, like 
everything else, have a history. Old rocks hold the key to the age of the 
earth; younger ones the clue to the origin of species. With Hugh Miller 
we observe the history of the earth's crust spread before us, in massive blocks 
of gneiss and hornblende and sedimentary beds of sandstone and shale. It is 
charming autobiography from one of the classics of geology. 

In the different types of rocks, Sir Archibald Geike can trace the story of 
bygone ages. In the remarkable Geological Change, this famous nineteenth 
century scientist describes the fundamentals of geology. He tells of the 
rhythmic cycles caused by alternate erosion and uplifting of land. He tells of 
the catastrophic changes which give rise to Earthquakes described by Father 
Macelwane, or ferocious volcanic eruptions like that which doomed forty 
thousand lives in St. Pierre, ironically saving the one man who was in /ail. 

In the organic remains, the fossils, laid down in stratified rock, Geike 
discerns forms now extinct the ferns and conifers of which Peattie writes 
in a later part; the scales of fishes found by Hugh Miller; the remains of 
dinosaurs that once roamed the earth; even the fragments of prehistoric man, 
the missing links about which you may read in Part Five. 

Finally, like Paul B. Sears in Man, Maker of Wilderness, Geike watches 
the effects of erosion on the land. Here is a clue to the decay of those civili- 
zations which permit man to take everything from the earth, giving noth- 
ing in return. 

We have removed from Geological Change a section on the celebrated 
nineteenth century controversy between the physicists and the geologists 
about the age of the earth. The age set by the physicists, led by Lord Kelvin, 
was far too short for the very slow and gradual changes the geologists 


envisaged. That controversy was settled by the discovery of radium. It's dis- 
integration furnished a source of energy the physicists had not taken into 
their calculations. And its slow change into a unique type of lead within a 
set period has furnished a valuable new geological clock. Examination of 
radioactive substances in the oldest rocks now leads us to assign a period of 
about 1,500,000,000 to 2,000,000,000 years as the age of the earth. 

If we would understand the wind and the rain, we must know What 
Makes the Weather. In aviation and agriculture and a thousand other activi- 
ties, it is a problem of vital importance. In long range history, it may mean 
climatic change that can alter the surface of a hemisphere. Here are the 
modern theories about cold fronts and air masses. Here are the ideas which 
help the weatherman become a successful prophet. 


In 1642, when Galileo died an old and disillusioned man, he had already 
learned a great deal about the mathematical meaning of motion. But he still 
did not understand why the planets moved around the sun. He could not 
know that in that same year a baby would be born who would create a world 
conforming to both mathematical and physical law. 

On Christmas Day, 1642, Isaac Newton was born in the village of Wools- 
thorpe in Lincolnshire, a premature, frail baby, the posthumous son of a 
yoeman farmer. Despite expectations to the contrary, he lived, and became the 
greatest scientist in history. He was to discover the law of gravitation, the 
laws of motion, the principles of optics, the composite nature of light, and 
with Leibnitz to invent the calculus. He of course owed a great debt to 
Galileo and to two other astronomers who lived in this same extraordinary 
period: Tycho Brahe, who first recorded accurately the motions of the plan- 
ets; and Johann Kepler whose laws of planetary motion showed how these 
planets moved with relation to their central sun. On the foundations laid by 
these three, Newton built a conception of the world and the forces that 
guide it that was destined to hold undisputed place until the beginning of 
the twentieth century, and even at that distant date to undergo but minor 

Newtoniana tells us something of the man; while Discoveries gives us all 
too brief glimpses of the work that made him what he was. 

The Physical Laws of the world are not easy to comprehend. Mathematics, 
physics and chemistry are so bound up with mysterious symbolism, not diffi- 
cult in itself but unintelligible to those who have not learned its secret, 
that words cannot give their full meaning. Yet meaning they do have, even 
for the layman. Much of it is conveyed in the selections that follow. 

First, let us consider mathematics, the foundation of physical law, the 
indispensable tool of the scientist. It transforms indefinite thoughts into 
specific theories. With its advance has come the advance of civilization. In 


remote ages primitive man learned to count; later to measure; finally to cal- 
culate. So we come to the modern world of science, where man must be a 
"calculating animal" if he is to understand physical and even biological 
science. Hogben tells something of the story in Mathematics, the Mirror of 

From mathematics we turn to physics. But before we do so, let us consider 
the Experiments and Ideas of that protean American Ben Franklin. He is 
best known for his work with electricity, with kites and lightning rods. Few 
remember his bifocal glasses, his discovery of the origin of northeast storms, 
his extraordinary prophecy of aerial invasion. 

In physics, we run squarely against one of the fundamental scientific prob- 
lems of the century: what goes on inside the atom? In Exploring the Atom, 
Sir James Jeans describes this strange world which all of us have heard about 
yet few understand. He shows how our nineteenth century concept of the 
atom as a sort of indestructible brick has been changed completely; he 
makes the new picture of the atom really clear. And in doing so, he gives us 
the basic knowledge which we must have to understand atomic fission and 
the atomic bomb. 

E. O. Lawrence, the California scientist who developed the world-famous 
cyclotron, has become one of the leaders in research on atomic fission. Long 
before our entrance into the war, his famous machine had "smashed the 
atom/' In Touring the Atomic World, Henry Schacht gives a description of 
his technique which the layman can understand. Not so long after this 
article was written, wartime secrecy shrouded the work of Lawrence and 
other nuclear physicists. The veil was lifted when a bomb exploded over 
Hiroshima. It is interesting to note how much research went into the subject, 
long before its military implications were thought of. 

The first clue to the breaking up of the atomic nucleus was given by those 
radioactive substances which disintegrate spontaneously. Jeans and Schacht 
have told us something about them; and now we come to the work of that 
extraordinary woman, Marie Curie, who kept house, brought up a family, 
and discovered radium. The Discovery of Radium is a story which gains new 
meaning when it is related to the course of modern physics. 

It is impossible to think of the question of matter apart from the equally 
fundamental one of energy. "Almost every problem of living turns out in the 
last analysis to be a problem of the control of energy/' writes George Russell 
Harrison of M. I. T. In The Taming of Energy, he tells us something of how 
the various forms are interrelated. The question is complicated by Einstein, 
who says that matter and energy are related according to mathematical law. 
That relationship is deep water indeed, as is all relativity theory. Yet in Space, 
Time and Einstein, Dr. Heyl, the man who weighed the earth, says interest- 
ing things about relativity which are not too difficult for the informed lay- 


As physics and chemistry continue to advance, it becomes harder to decide 
where one begins and the other ends. In the eighteenth century when 
Lavoisier, "Father of Modern Chemistry/' died on the guillotine because the 
French Revolution had "no need for scientists/' there was little connection. 
In the nineteenth, when Mendeteef set up his periodic table, the gulf re- 
mained. Basic work dealt with discovering and arranging the elements. In 
the periodic table, Mendeteef arranged the elements according to their atomic 
weights in somewhat the same way that the days of the month are arranged 
on a calendar. When this was done, the elements in any vertical column 
(the Sundays or Fridays) resembled one another in basic chemical properties. 
As many elements had not been discovered, it was necessary to leave gaps in 
the table. He prophesied that some day these gaps would be filled by ele- 
ments which were then unknown, and this is exactly what has happened. 

There is another aspect of chemistry which is perhaps of greater interest 
to the lay reader its application to everyday life. On chemical reactions 
depend practically all industrial processes of the present day. On the re- 
arrangement of atoms and molecules of substances which occur in nature, 
depends the creation of the synthetics which are becoming an inseparable 
part of our lives. One subject is discussed by the director of the Du Pont 
laboratories in The Foundations of Chemical Industry; the other by the 
Science Editor of the New York Times in The Chemical Revolution. 

Finally comes the all-absorbing question of the war. Many weapons of 
scientific warfare are held in greatest secrecy by various powers. But many 
others can be discussed because they are known to all. 

In Jets Power Future Flying, Watson Davis, the Director of Science 
Service, the country's leading organization for the general dissemination of 
scientific information, describes the various techniques whereby jet propul- 
sion is revolutionizing aviation. In Science in War and After, Dr. Harrison 
tells us about tanks that are tougher, aerial photography that sees farther, 
naval guns that shoot straighter, and radio locators that see where human 
eyes are useless. 


A Theory that the Earth Moves Around the Sun 


From Concerning the Revolutions of the Heavenly Bodies 



JL spherical; partly because this form, being a complete whole, needing 
no joints, is the most perfect of all; partly because it constitutes the most 
spacious form, which is thus best suited to contain and retain all things; 
or also because all discrete parts of the world, I mean the sun, the moon 
and the planets, appear as spheres; or because all things tend to assume 
the spherical shape, a fact which appears in a drop of water and in other 
fluid bodies when they seek of their own accord to limit themselves. 
Therefore no one will doubt that this form is natural for the heavenly 


That the earth is likewise spherical is beyond doubt, because it presses 
from all sides to its center. Although a perfect sphere is not immediately 
recognized because of the great height of the mountains and the depres- 
sion of the valleys, yet this in no wise invalidates the general spherical 
form of the earth. This becomes clear in the following manner: To 
people who travel from any place to the North, the north pole of the 
daily revolution rises gradually, while the south pole sinks a like amount. 
Most of the stars in the neighborhood of the Great Bear appear not to 
set, and in the South some stars appear no longer to rise. Thus Italy 
does not see Canopus, which is visible to the Egyptians. And Italy sees 
the outermost star of the River, which is unknown to us of a colder zone. 
On the other hand, to people who travel toward the South, these stars 
rise higher in the heavens, while those stars which are higher to us 



become lower. Therefore, it is plain that the earth is included between 
the poles and is spherical. Let us add that the inhabitants of the East do 
not see the solar and lunar eclipses that occur in the evening, and people 
who live in the West do not see eclipses that occur in the morning, while 
those living in between see the former later, and the latter earlier. 

That even the water has the same shape is observed on ships, in that 
the land which can not be seen from the ship can be spied from the tip 
of the mast. And, conversely, when a light is put on the tip of the mast, 
it appears to observers on land gradually to drop as the ship recedes until 
the light disappears, seeming to sink in the water. It is clear that the 
water, too, in accordance with its fluid nature, is drawn downwards, just 
as is the earth, and its level at the shore is no higher than its convexity 
allows. The land therefore projects everywhere only as far above the 
ocean as the land accidentally happens to be higher. . . . 


Since it has already been proved that the earth has the shape of a 
sphere, I insist that we must investigate whether from its form can be 
deduced a motion, and what place the earth occupies in the universe. 
Without this knowledge no certain computation can be made for the 
phenomena occurring in the heavens. To be sure, the great majority of 
writers agree that the earth is at rest in the center of the universe, so that 
they consider it unbelievable and even ridiculous to suppose the contrary. 
Yet, when one weighs the matter carefully, he will see that this question 
is not yet disposed of, and for that reason is by no means to be considered 
unimportant. Every change of position which is observed is due either 
to the motion of the observed object or of the observer, or to motions, 
naturally in different directions, of both; for when the observed object 
and the observer move in the same manner and in the same direction, 
then no motion is observed. Now the earth is the place from which we 
observe the revolution of the heavens and where it is displayed to our 
eyes. Therefore, if the earth should possess any motion, the latter would 
be noticeable in everything that is situated outside of it, but in the 
opposite direction, just as if everything were traveling past the earth. 
And of this nature is, above all, the daily revolution. For this motion 
seems to embrace the whole world, in fact, everything that is outside of 
the earth, with the single exception of the earth itself. But if one should 
admit that the heavens possess none of this motion, but that the earth 
rotates from west to east; and if one should consider this seriously with 
respect to the seeming rising and setting of the sun, of the moon and 


the stars; then one would find that it is actually true. Since the heavens 
which contain and retain all things are the common home of all things, 
it is not at once comprehensible why a motion is not rather ascribed to 
the thing contained than to the containing, to the located rather than to 
the locating. This opinion was actually held by the Pythagoreans Heraklid 
and Ekphantus and the Syracusean Nicetas (as told by Cicero), in that 
they assumed the earth to be rotating in the center of the universe. They 
were indeed of the opinion that the stars set due to the intervening of 
the earth, and rose due to its receding. . . . 


It is claimed that the earth is at rest in the center of the universe and 
that this is undoubtedly true. But one who believes that the earth rotates 
will also certainly be of the opinion that this motion is natural and not 
violent. Whatever is in accordance with nature produces effects which 
are the opposite of what happens through violence. Things upon w r hich 
violence or an external force is exerted must become annihilated and 
cannot long exist. But whatever happens in the course of nature remains 
in good condition and in its best arrangement. Without cause, therefore, 
Ptolemy feared that the earth and all earthly things if set in rotation 
would be dissolved by the action of nature, for the functioning of nature 
is something entirely different from artifice, or from that which could 
be contrived by the human mind. But why did he not fear the same, and 
indeed in much higher degree, for the universe, whose motion would 
have to be as much more rapid as the heavens are larger than the earth? 
Or have the heavens become infinite just because they have been removed 
from the center by the inexpressible force of the motion; while otherwise, 
if they were at rest, they would collapse? Certainly if this argument 
were true the extent of the heavens would become infinite. For the more 
they were driven aloft by the outward impulse of the motion, the more 
rapid would the motion become because of the ever increasing circle 
which it would have to describe in the space of 24 hours; and, con- 
versely, if the motion increased, the immensity of the heavens would also 
increase. Thus velocity would augment size into infinity, and size, 
velocity. But according to the physical law that the infinite can neither 
be traversed, nor can it for any reason have motion, the heavens would, 
however, of necessity be at rest. 

But it is said that outside of the heavens there is no body, nor place, 
nor empty space, in fact, that nothing at all exists, and that, therefore, 
there is no space in which the heavens could expand; then it is really 
strange that something could be enclosed by nothing. If, however, the 
heavens were infinite and were bounded only by their inner concavity, 


then we have, perhaps, even better confirmation that there is nothing 
outside of the heavens, because everything, whatever its size, is within 
them; but then the heavens would remain motionless. The most impor- 
tant argument, on which depends the proof of the finiteness of the 
universe, is motion. Now, whether the world is finite or infinite, we will 
leave to the quarrels of the natural philosophers; for us remains the 
certainty that the earth, contained between poles, is bounded by a spher- 
ical surface. Why should we hesitate to grant it a motion, natural and 
corresponding to its form; rather than assume that the whole world, 
whose boundary is not known and cannot be known, moves? And why 
are we not willing to acknowledge that the appearance of a daily revolu- 
tion belongs to the heavens, its actuality to the earth? The relation is 
similar to that of which Virgil's /Eneas says: "We sail out of the harbor, 
and the countries and cities recede." For when a ship is sailing along 
quietly, everything which is outside of it will appear to those on board 
to have a motion corresponding to the movement of the ship, and the 
voyagers are of the erroneous opinion that they with all that they have 
with them are at rest. This can without doubt also apply to the motion 
of the earth, and it may appear as if the whole universe were revolving 


. . . Since nothing stands in the way of the movability of the earth, 
I believe we must now investigate whether it also has several motions, 
so that it can be considered one of the planets. That it is not the center 
of all the revolutions is proved by the irregular motions of the planets, 
and their varying distances from the earth, which cannot be explained 
as concentric circles with the earth at the center. Therefore, since there 
are several central points, no one will without cause be uncertain 
whether the center of the universe is the center of gravity of the earth 
or some other central point. I, at least, am of the opinion that gravity 
is nothing else than a natural force planted by the divine providence of 
the Master of the World into its parts, by means of which they, assuming 
a spherical shape, form a unity and a whole. And it is to be assumed that 
the impulse is also inherent in the sun and the moon and the other 
planets, and that by the operation of this force they remain in the spherical 
shape in which they appear; while they, nevertheless, complete their 
revolutions in diverse ways. If then the earth, too, possesses other motions 
besides that around its center, then they must be of such a character as 
to become apparent in many ways and in appropriate manners; and 
among such possible effects we recognize the yearly revolution. 


Proof that the Earth Moves 


From The Sidereal Messenger 

<L\. ears that a Dutchman had constructed a telescope, by the aid of 
which visible objects, although at a great distance from the eye of the 
observer, were seen distinctly as if near; and some proofs of its most 
wonderful performances were reported, which some gave credence to, 
but others contradicted. A few days after, I received confirmation of the 
report in a letter written from Paris by a noble Frenchman, Jaques 
Badovere, which finally determined me to give myself up first to inquire 
into the principle of the telescope, and then to consider the means by 
which I might compass the invention of a similar instrument, which 
after a little while I succeeded in doing, through deep study of the theory 
of Refraction; and I prepared a tube, at first of lead, in the ends of 
which I fitted two glass lenses, both plane on one side, but on the other 
side one spherically convex, and the other concave. Then bringing my 
eye to the concave lens I saw objects satisfactorily large and near, for 
they appeared one-third of the distance off. and nine times larger than 
when they are seen with the natural eye alone. I shortly afterwards con- 
structed another telescope with more nicety, which magnified objects 
more than sixty times. At length, by sparing neither labour nor expense, 
I succeeded in constructing for myself an instrument so superior that 
objects seen through it appear magnified nearly a thousand times, and 
more than thirty times nearer than if viewed by the natural powers of 
sight alone. 


It would be altogether a waste of time to enumerate the number and 
importance of the benefits which this instrument may be expected to 



confer, when used by land or sea. But without paying attention to its 
use for terrestrial objects, I betook myself to observations of the heavenly 
bodies; and first of all, I viewed the Moon as near as if it was scarcely 
two semidiameters of the Earth distant. After the Moon, I frequently 
observed other heavenly bodies, both fixed stars and planets, with 
incredible delight. . . . 


There remains the matter, which seems to me to deserve to be con- 
sidered the most important in this work, namely, that I should disclose 
and publish to the world the occasion of discovering and observing four 
planets, never seen from the very beginning of the world up to our own 
times, their positions, and the observations made during the last two 
months about their movements and their changes* of magnitude. . . . 

On the yth day of January in the present year, 1610, in the first hour 
of the following night, when I was viewing the constellations of the 
heavens through a telescope, the planet Jupiter presented itself to my 
view, and as I had prepared for myself a very excellent instrument, I 
noticed a circumstance which I had never been able to notice before, 
owing to want of power in my other telescope, namely,, that three little 
stars, small but very bright, were near the planet; and although I 
believed them to belong to the number of the fixed stars, yet they made 
me somewhat wonder, because they seemed to be arranged exactly in a 
straight line, parallel to the ecliptic, and to be brighter than the rest 
of the stars, equal to them in magnitude. The position of them with 
reference to one another and to Jupiter was as follows: 

Ori. * * O * Occ. 

On the east side there were two stars, and a single one towards the west. 
The star which was furthest towards the east, and the western star, 
appeared rather larger than the third. 

I scarcely troubled at all about the distance between them and Jupiter, 
for, as I have already said, at first I believed them to be fixed stars; but 
when on January 8th, led by some fatality, I turned again to look at 
the same part of the heavens, I found a very different state of things, 
for there were three little stars all west of Jupiter, and nearer together 
than on the previous night, and they were separated from one another 
by equal intervals, as the accompanying figure shows. 


Ori. O * * * Occ. 

At this point, although I had not turned my thoughts at all upon the 
approximation of the stars to one another, yet my surprise began to be 
excited, how Jupiter could one day be found to the east of all the afore- 
said fixed stars when the day before it had been west of two of them; 
and forthwith I became afraid lest the planet might have moved differ- 
ently from the calculation of astronomers, and so had passed those stars 
by its own proper motion. I, therefore, waited for the next night with the 
most intense longing, but I was disappointed of my hope, for the sky 
was covered with clouds in every direction. 

But on January loth the stars appeared in the following position with 
regard to Jupiter, the third, as I thought, being 

Ori. * * O Occ. 

hidden by the planet. They were situated just as before, exactly in the 
same straight line with Jupiter, and along the Zodiac. 

When I had seen these phenomena, as I knew that corresponding 
changes of position could not by any means belong to Jupiter, and as, 
moreover, I perceived that the stars which I saw had always been the 
same, for there were no others either in front or behind, within a great 
distance, along the Zodiac at length, changing from doubt into surprise, 
I discovered that the interchange of position which I saw belonged not to 
Jupiter, but to the stars to which my attention had been drawn, and I 
thought therefore that they ought to be observed henceforward with 
more attention and precision. 

Accordingly, on January nth I saw an arrangement of the follow- 
ing kind: 

Ori. * * O Occ. 

namely, only two stars to the east of Jupiter, the nearer of which was dis- 
tant from Jupiter three times as far as from the star further to the east; 
and the star furthest to the east was nearly twice as large as the other 
one; whereas on the previous night they had appeared nearly of equal 
magnitude. I, therefore, concluded, and decided unhesitatingly, that there 
are three stars in the heavens moving about Jupiter, as Venus and 
Mercury round the Sun; which at length was established as clear as 
daylight by numerous other subsequent observations. These observations 


also established that there are not only three, but four, erratic sidereal 
bodies performing their revolutions round Jupiter. . . . 

These are my observations upon the four Medicean planets, recently 
discovered for the first time by me; and although it is not yet permitted 
me to deduce by calculation from these observations the orbits of these 
bodies, yet I may be allowed to make some statements, based upon them, 
well worthy of attention. 


And, in the first place, since they are sometimes behind, sometimes 
before Jupiter, at like distances, and withdraw from this planet towards 
the east and towards the west only within very narrow limits of 
divergence, and since they accompany this planet alike when its motion 
is retrograde and direct, it can be a matter of doubt to no one that they 
perform their revolutions about this planet while at the same time they 
all accomplish together orbits of twelve years' length about the centre 
of the world. Moreover, they revolve in unequal circles, which is evi- 
dently the conclusion to be drawn from the fact that I have never been 
permitted to see two satellites in conjunction when their distance from 
Jupiter was great, ^whereas near Jupiter two, three, and sometimes all 
four, have been found closely packed together. Moreover, it may be 
detected that the revolutions of the satellites which describe the smallest 
circles round Jupiter are the most rapid, for the satellites nearest to 
Jupiter are often to be seen in the east, when the day before they have 
appeared in the west, and contrariwise. Also, the satellite moving in the 
greatest orbit seems to me, after carefully weighing the occasions of its 
returning to positions previously noticed, to have a periodic time of half 
a month. Besides, we have a notable and splendid argument to remove 
the scruples of those who can tolerate the revolution of the planets 
round the Sun in the Copernican system, yet are so disturbed by the 
motion of one Moon about the Earth, while both accomplish an orbit 
of a year's length about the Sun, that they consider that this theory of 
the universe must be upset as impossible; for now we have not one 
planet only revolving about another, while both traverse a vast orbit 
about the Sun, but our sense of sight presents to us four satellites circling 
about Jupiter, like the Moon about the Earth, while the whole system 
travels over a mighty orbit about the Sun in the space of twelve years. 


The Orderly Universe 


shining objects are seen the sun by day, the moon and numerous 
stars at night. In comparison with the enormous earth beneath our feet, 
they all appear to be insignificant bodies. Indeed, the sun and the moon 
are often hidden from our view by a passing cloud, while the stars are 
only scintillating points of light. Not only do the heavenly bodies appear 
to be relatively small, but men in all ages almost down to our own have 
believed that they are small. The general conception of the relative impor- 
tance of the various bodies in the cosmos is illustrated by the story of 
creation in Genesis. According to this account, after the earth had been 
created, "God made two great lights" in the sky above, "the greater light 
to rule the day, and the lesser light to rule the night." And then, almost 
as if it were an afterthought, "he made the stars also." 

Often in the history of science it has been found that "things are not 
what they seem." It has been so in the history of astronomy to a marked 
degree. Perhaps in no other field of exploration have the differences 
between appearances and realities been so great. On the one hand, this 
apparently limitless planet on which we dwell has been reduced relatively 
to a particle of dust floating in the immensity of space; while, on the 
other hand, "the greater light," hanging like a lamp in the sky, has been 
expanded to a flaming mass of gas a million times greater in volume than 
the earth. More remarkable still, the tiny twinkling stars, instead of being 
fireflies of the heavens, are in reality other suns, many greater than our 
own, whose glories are dimmed only by their enormous distances from 
us; and the soft circle of light which we know as the Milky Way has 
been found to be a vast cosmic system of twenty thousand million stars. 

Amazing are the differences between what the heavenly bodies appear 
to be and what they actually are. Equally amazing are the differences 
between the intervals of time within the range of direct human experience 



and the enormous periods covered by the cosmic processes. Historians 
speak of the civilizations which long ago flourished in the valleys of the 
Nile and the Euphrates as being ancient, and from the standpoint of 
human history they are ancient. Yet all the written records which arche- 
ologists have recovered from the buried ruins of long-forgotten cities 
date back less than ten thousand years, which is only a moment in com- 
parison with the millions of years of the geological eras or with the three 
thousand million years during which the earth has existed as a separate 
body. Even the great age of the earth is only a small fraction of the 
enormous lifetime of a star. 

Great distances, prodigious masses, and long intervals of time are not 
merely interesting. They stir our imaginations, exercise our reasoning 
powers, expand our spirits, and change our perspective with respect to 
all the experiences of life. But they do not include all the important conse- 
quences of astronomical investigations. Indeed, they do not directly 
include that which is most important, the supreme discovery of science 
the orderliness of the universe. 

What do we mean by "the orderliness of the universe"? Astronomers 
found from painstaking and long-continued observations of the heavenly 
bodies that celestial phenomena recur in regular sequences. Though the 
order of the succession of events in the heavens is often somewhat com- 
plex, it is nevertheless systematic and invariable. The running of no clock 
ever approached in precision the motions of the sun, the moon, and the 
stars. In fact, to this day clocks are corrected and regulated by comparing 
them with the apparent diurnal motions of the heavenly bodies. Since not 
merely a few but hundreds of celestial phenomena were long ago found 
to be perfectly orderly, it was gradually perceived that majestic order 
prevails universally in those regions in which, before the birth of science, 
capricious gods and goddesses were believed to hold dominion. . . . 


For a few days each month the crescent moon may be seen after sunset 
in the western sky. In a week it changes to a semicircle of light directly 
south on the meridian at the same hour; in another week, at the full 
phase, it rises in the east as the sun sets. If observations are continued 
through the night, the full moon is found directly south at midnight, and 
setting in the west as the sun rises. Year after year and century after 
century this shining body goes through its cycles of changes, each cycle 
being generally similar to the others but no two of them being exactly 
alike. It is not surprising that primitive peoples should have regarded it 
with awe and determined the times of their religious ceremonies by its 


phases. Indeed, most of the calendars of antiquity were based upon the 
phases of the moon. 

Regularities in the motions of the moon and in the succession of its 
phases have always been found by those who have carefully followed 
celestial phenomena. But these approximations to cyclical repetitions are 
only crude hints of the perfect orderliness which accurate and long- 
continued astronomical observations have proved to exist. Every apparent 
departure from some simple theory has been found to be a part of a 
greater and more complicated order. The observed motion of the moon 
is compounded out of more than a thousand cycles whose magnitudes 
and phases are now accurately known. The theory of the motion of the 
moon is so perfect that its position can be computed for any instant in 
the future, even for a thousand years. Indeed, it is obvious that if it were 
not possible for mathematicians to compute accurately the motions of the 
moon, they could not unerringly predict all the circumstances of eclipses 
many years in advance of their occurrence. 

Astronomers have not simply worked out the properties of the motion 
of the moon from observations of its positions over long intervals of time. 
They have discovered the underlying reason for all the complexities of its 
path about the earth, and that reason is that it moves subject to the 
gravitational attraction of the earth and, to a lesser degree, of the more 
distant sun. This force which prevents the moon from flying away from 
the earth is sufficient to break a steel cable nearly three 'hundred miles 
in diameter. Yet invisibly, like the force between a magnet and a piece of 
iron, it acts across the 240,000 miles between the earth and the moon. 
With extraordinary exactness it varies inversely as the square of the 
distance between these bodies. Together with the attraction of the sun 
on the earth and the moon, it forms an infallible basis for explaining all 
the peculiarities of the motion of our satellite. Indeed, in numerous 
instances it has enabled mathematicians to anticipate experience and to 
predict phenomena which observations later confirmed. 

Mere words cannot do justice to the marvelous agreement between 
theory and the actual motions of the moon. No machine ever ran with 
such accuracy; no predictions of terrestrial phenomena were ever so per- 
fectly fulfilled. If we are entitled to conclude that we understand any- 
thing whatever, we may claim that we understand how the moon moves 
around the earth under the attractions of the earth and the sun. . . . 

Evidently the moon is above the level of the highest clouds and far 
away from the earth. It is easy to understand that if two astronomers are 
at two different points, they will see the moon in somewhat different 
directions from their points of observation: and it is almost as easy to 


understand that from the distance between the astronomers and the 
angle at which the moon is observed its altitude above the earth can 
be computed. From such observations and calculations, astronomers have 
found that the distance from the center of the earth to the center of the 
moon varies between 225,000 and 252,000 miles, with an average of 238,857 
miles. This distance is known with nearly the same percentage of accuracy 
as the diameter of the earth. The moon moves at an average speed of 
3,350 feet per second in an orbit so large that in going this distance it 
deviates from a straight line only about one twentieth of an inch. 

After the distance to the moon has been determined, its diameter can 
be computed from its apparent size. This shining object which even a 
small button held at arm's length will hide from view is actually 2,160 
miles in diameter, or more than one fourth the diameter of the earth. 
Its exterior area is approximately thirty million square miles, or ten 
times the area of the United States. Consequently, there is abundant room 
on its surface for mountains and valleys and plains and lakes and seas. 
There are, indeed, many mountains on the moon's surface, both isolated 
peaks and long ranges, and there are valleys and plains, but no lakes or 
seas. In fact, there is no water whatever upon its surface, nor is there even 
an atmosphere surrounding it. 

There is no real mystery respecting the lack of air and water on the 
moon. The surface gravity of this small world (about one sixth that of 
the earth) is not sufficient to hold the swiftly darting molecules of an 
atmosphere from escaping away into space. Its surface is a desert, unpro- 
tected by clouds or an atmosphere from the burning rays of the sun 
during its day, or from the rapid escape of heat during its night. Both 
extremes of its surface temperature are particularly severe, because its 
period of rotation is about 29.5 times that of the earth. For nearly fifteen 
of our days a point on its surface is subjected to a temperature above the 
boiling point of water on the earth; for an equal interval of time it freezes 
in a temperature which descends far toward the absolute zero (about 
460 Fahrenheit), Evidently it cannot be the abode of life. . . . 


From a certain point of view the earth is for us a very important body, 
more important than every celestial body except the sun. It has been the 
home of the life stream of which we are a part for more than a thousand 
million years. It will be the home of our successors until our race becomes 
extinct. Our very existence depends upon it. 

From another point of view, which we shall now take, the earth is not 
very important. It is only one of nine known planets which revolve 


around the sun, each of them held in its orbit by the attraction of the 
great central mass. Thus, the very brilliant silvery object which we see 
in the western evening sky (and eastern morning sky) every nineteen 
months is the planet Venus, a world in size and in most other respects 
similar to our earth. The wandering conspicuous red body which appears 
in the evening sky every twenty-six months is the planet Mars, and the 
brighter yellowish object which returns every thirteen months is Jupiter. 
These bodies and two others, Mercury and Saturn, were called planets 
(or wanderers) by the ancients because they are constantly moving with 
respect to the stars. . . . 

It was not until the first decades of the seventeenth century that Kepler 
worked out from the observations of Tycho Brahe the properties of the 
planetary orbits; it was not until the latter part of the same century that 
Newton proved the law of gravitation and explained by means of it the 
motions of the planets and of the moon, the oblateness of the earth, and 
the ebb and flow of the tides. These great achievements mark the closing 
of an epoch in the history of the thought of the world and the beginning 
of a new, for they entirely overthrew earlier views respecting the nature 
of the cosmos and established others which were entirely different. They 
permanently removed man from his proud position at the center of crea- 
tion and placed him on a relatively insignificant body; but, as a compen- 
sation, they rescued him from a universe of chance and superstition and 
gave him one of unfailing and majestic orderliness. 

There have been many impressive illustrations of the orderliness of 
the universe and of our understanding of that order, but none has been 
more dramatic than the discovery of Neptune. This remarkable story 
opened in 1781 with the discovery of the planet Uranus (the first one 
discovered in historic times) by William Herschel; it closed with the 
discovery of Neptune in 1846. 

After Uranus had been observed for a few months, mathematicians 
computed its orbit and directed observers where to point their telescopes 
in order to see this planet, for it is too faint to be observable with the 
unaided eye. For nearly forty years Uranus was always found precisely 
where the mathematicians said it would be seen. Then there began to be 
an appreciable difference between theory and the observations. By 1830 
the discrepancies had become serious; by 1840 they were intolerably large. 
Although the discrepancies were intolerably large to scientists they would 
have been negligible to anyone else in the world. During the sixty years 
following the discovery of Uranus it did not depart from its predicted 
positions by an amount large enough to be observable without the aid 
of a telescope. Since mankind had never even known of the existence 


of Uranus until 1781, it at first seems absurd that scientists should have 
been disturbed by very minute unexplained peculiarities in its motions 
variations from theory so slight that they were not observable until the 
lapse of about forty years. The theories, however, were believed to be 
very perfect. Hence the discrepancies called into question their exactness, 
or perhaps even the soundness of mathematical reasoning. In fact, the 
unexplained difference between theory and observation threw a doubt 
on our ability to discover and to apply the laws of nature. For this reason 
the motion of Uranus became one of the most important problems in 

In 1846 order was restored by a brilliant discovery. Some years earlier 
it had been suggested that Uranus was departing slightly from its pre- 
dicted orbit as the consequence of the attraction of an unknown world. The 
problem was to find the unknown body from its minute effects on Uranus. 
No brief statement can give any adequate realization of the difficulties 
of the problem. The leading mathematicians of the time thought it could 
not be solved. But two young men, J. C. Adams, of England, and U. J. 
Leverrier, of France, inspired with the optimism and energy of youth, 
calculated where the unknown world would be found. Their predictions 
were brilliantly fulfilled by the discovery of Neptune on February 23, 
1846, by J. G. Galle, a young German astronomer. With this discovery, 
the motion of Uranus again was fully explained, the laws of nature and 
our reasoning powers were no longer in question, and the universe was 
once more orderly. . . . 

No experiences give us a better understanding of distances than those 
obtained from long journeys. Consequently, let us in imagination board 
some miraculous skyship, of which everyone has often dreamed, and 
travel from the sun to the various planets. 

Obviously our skyship must fly rapidly or we shall not live long enough 
to cross the great distance from one planet to another. On the other hand, 
if it travels at too great speed we shall not be able to descend safely upon 
the surface of a planet. So let us suppose our skyship can traverse the 
interplanetary spaces at the rate of a thousand miles per hour, a speed of 
travel at which one might eat breakfast in the eastern part of the United 
States and luncheon in Europe. Let us start from the surface of the sun. 
Perhaps before directing our way toward Mercury we should circle around 
this great center of attraction. Jauntily we set out and travel continuously, 
but we do not complete the circuit of the sun and get back to our point 
of departure until 113 days, or nearly four months, have elapsed. 

With some trepidation at leaving the sun and plunging into the inter- 
planetary spaces, we depart for Mercury, which we reach in four years and 


one month. In three and one half years we are at the distance of Venus; 
in three more at the orbit of the earth, ten years and seven months after 
we left the sun. Since five years and seven months more are required to 
reach Mars from the orbit of the earth, it takes our skyship sixteen years 
and two months to fly from the sun to this planet. Obviously the intervals 
of time required for these sky voyages are so great that they fail to give us 
any real understanding of the enormous distances we traverse. Yet let us 
continue* on our way. 

We arrive at Jupiter in fifty-five years after we left the sun; at Saturn in 
lor years; at Uranus in 203 years; and at Neptune in 318 years. If we 
should continue to distant and inconspicuous Pluto, we should arrive there 
in 420 years. And yet at the rate of our travel we could eat breakfast in 
New York, luncheon in London, and return to New York for dinner anc 
the theater. . . . 


Since the* dawn of history and, indeed, for millions of years before the 
origin of man, the sun and the moon have not changed appreciably in 
appearance. But there are celestial visitors, the comets, which do not 
possess these qualities of permanence and uniformity from which the 
orderliness of the universe was first perceived. These objects often come 
quite unexpectedly out of the depths of space for a brief visit to the inte- 
rior of the solar system, and then they recede back into the night from 
which they came. They are not of fixed shape or constant dimensions like 
the planets. The typical comet consists of a small nucleus, generally star- 
like in appearance, surrounded by a vast gaseous envelope which varies 
enormously in volume, sometimes being as large as the sun; while from its 
head there streams out a tail, perhaps fifty millions of miles in length, 
which in exceptional cases appears to reach a third of the way across the 

It is not strange that primitive peoples and, indeed, all men until only 
two or three centuries ago regarded comets with superstitious fear. Our 
predecessors believed that these bizarre-appearing objects are malignant 
spirits prowling through our atmosphere, or at least that they are portents 
of wars and pestilences. After centuries of belief in these superstitions, 
accepted alike by the ignorant and the learned, by theologians and 
scientists, observations led finally to the truth. 

Tycho Brahe (1571-1630), the greatest and last observer before the inven^ 
tion of the telescope, comparing the different apparent directions of the 
comet of 1577 as seen simultaneously from various places in Europe, 
proved that this terrifying object was far beyond our atmosphere and at 


least as distant as the moon. By this demonstration he removed comets 
from the apparent vagaries of atmospheric phenomena to the orderly 
domains of the celestial bodies. 

It should not be thought that comets and thqjr motions were at once 
completely understood. The phenomena they present are far too com- 
plicated for an easy explanation. In fact, the determination of the proper- 
ties of their paths through the solar system had to await Newton's dis- 
covery of the law of gravitation in 1686 and his use of it in explaining the 
celestial motions. He devised methods of determining the orbits of comets, 
however elongated they might be. 

A lifelong friend of Newton, Edmund Halley, applied Newton's 
methods to computing the orbit of a great comet which had been observed 
in 1682. After an enormous amount of work on this and earlier comets, 
he proved that it revolves in a very elongated path, returning to the neigh- 
borhood of the sun about every seventy-five years. He concluded that it 
was identical with comets which had been observed in 1456, 1301, 1145* 
1066, and at various other times; he boldly predicted it would return 
in 1759, and it did. It came again according to predictions in 1835, and 
most recently in 1910. Now it is far out in its long orbit. It has been 
invisible for twenty-five years and will not be seen again for forty years 
in the future. Yet mathematicians can follow it with perfect certainty, 
and long before its next return they will compute the very day when it 
will arrive at the point of its orbit nearest the sun. 

. . . Comets differ enormously from one another in brightness, volume, 
length of tails, and internal activity. From three to eleven comets are 
observed each year, nearly all of them being so faint as to be invisible 
without optical aid. Occasionally one appears which is bright enough to- 
be easily visible to the unaided eye; about three or four times a century 
a very great one becomes the most conspicuous object in the night sky. 
The tails of comets develop and increase in length as these objects 
approach the sun and diminish and disappear as they recede again* 
While a comet is approaching the sun, its tail streams out behind; as. 
it recedes, its tail projects out ahead of it. ... 


In comparison with the universe in general, only one object in the 
solar system is worth mentioning, and that object is the sun. It is a 
million times greater than the earth in volume and a thousand times 
greater in mass than all the planets combined. It holds the little planets 
under its gravitative control, it lights and warms them with its abun- 
dant rays, it takes them with it in its enormous excursions among the stars. 


How brilliant the light of the noonday sun is! In comparison with it 
all artificial lights are feeble and dull. How intensely it warms the sur- 
face of the earth on a summer's day! This general impression is not 
erroneous, for accurate jneasurements prove that when its rays fall per- 
pendicularly upon the surface of the earth radiant energy is received 
from it at the rate of 1.5 horsepower per square yard. Under the same 
condition of perpendicular rays, a square mile of surface receives radiant 
energy from the sun at the rate of 4,646,400 horsepower, or at the rate of 
330 million million (330,000,000,000,000) horsepower on the whole earth. 
If this energy were divided equally among the two billion human beings 
now living on the earth, each of them would have more than a hundred 
thousand horsepower for his use. 

As enormous as is the energy received by the earth from the sun, it is 
trivial compared with the amount radiated by the sun, for the earth as 
seen from the sun would appear to be only a point, somewhat smaller 
than Venus appears to us when it is the bright evening star. It is evident 
that such a distant and apparently insignificant object would intercept only 
a very small fraction of the solar energy streaming out from it in every 
direction. It is found by computation that the earth intercepts only one 
two-billionth of the energy radiated by the sun. Otherwise expressed, the 
sun radiates more energy in a second than the earth receives in sixty years. 

Obviously the sun must be very hot, for otherwise it would not radiate 
energy at an enormous rate. By several methods it is found that the tem- 
perature of its exterior radiating layers is about ten thousand degrees 
Fahrenheit, or far beyond the temperature required for melting and 
volatilizing iron and other similar substances. In its deep interior the 
temperatures are enormously higher, mounting to at least several million 

The temperature of the sun's interior has not, of course, been measured 
by any direct means, for the depths of the sun are quite inaccessible to us. 
But science often penetrates inaccessible regions by reasoning, as it does 
in this case. The general principles underlying the method used in this 
problem are as follows: Each layer of the sun weighs down upon the one 
directly beneath it and tends to compress it. This tendency to compression 
of a layer is balanced by the expansive forces due to its temperature. Now 
the rates of increase downward in both density and temperature can be 
determined by the condition that the entire mass of the sun shall be in 
equilibrium. The results are subject to some uncertainties, however, because 
of our lack of knowledge of the properties of matter under the extreme 
conditions of pressure and temperature prevailing deep in the sun. 

When we recall the terrestrial storms that are produced by unequal 


heating of different portions of the earth's atmosphere, we naturally ex- 
pect extremely violent disturbances on the sun. The wildest flights of our 
imagination, however, never approach the realities, for often masses of 
enormously heated gases a hundred times greater than the earth in volume 
shoot upward from its surface, sometimes farther than from the earth 
to the moon. Particularly in intermediate latitudes on each side of the solar 
equator there are storm zones in which great whirling sun spots appear. 
These sun-spot disturbances, ranging from a few thousand up to more 
than a hundred thousand miles in diameter, have centers which appear 
dark in contrast to the surrounding bright surface, though they are more 
luminous than the filament of an electric light. In them incandescent gases 
surge and billow, and from their borders eruptions to great altitudes are 
particularly abundant. If our earth were placed on the surface of the sun 
it would be tossed about like a pebble in a whirlpool; it would be melted 
and dissipated like a snowflake in a seething lake of lava. . . . 

If the sun were dissipating its mass into space, scientists would natu- 
rally inquire how it is restored, but until about 1850 they did not ask 
the same question respecting the energy it radiates. Until that time they 
did not realize that energy is something quantitative and measurable, and 
hence that its origin requires explanation. The sun cannot be a body which 
was once much hotter than at present and which is slowly cooling off, 
for if this were all there is to its heat it would not have lasted a thou- 
sandth of the long periods of the geological ages. It cannot be simply 
burning, for the heat produced by its combustion, even if it were composed 
of pure coal and oxygen, would last only a few thousand years. If it 
were contracting, the heat generated in the process would maintain its 
radiation only a few million years, which is less than one per cent of the 
interval during which it has shed its warm rays upon the earth at approxi- 
mately the present rate. 

Recently very conclusive reasons have been found for believing that the 
energy the sun radiates is due to transformations of its elements, partic- 
ularly of hydrogen, into heavier elements, and probably to the transforma- 
tion of matter into energy in accordance with Einstein's principle of the 
fundamental equivalence of mass and energy. These sources of energy are 
of an entirely different and higher order of magnitude than any hereto- 
fore considered by scientists. Although the mass equivalent of the energy 
radiated by the sun in a second is over 4,000,000 tons, the mass of the sun 
is so enormous that it will not be reduced through radiation by so much 
as one per cent in 150,000,000,000 years. Consequently, it is not surprising 
that the geological evidence is conclusive that the earth has received solar 
energy at substantially the present rate for perhaps a thousand million 


years. Even this long interval of time is only a very small fraction of the 
period during which the earth will continue in the future to be lighted 
and warmed by the sun almost precisely as it is at present. The fears once 
held that in a few million years the light of the sun will fail have proved 
groundless, and scientists no longer look forward to a time when the earth, 
cold and lifeless, will circulate endlessly around a dark center of attraction. 

One of the miracles of science has been the determination of the composi- 
tion of the sun. . . . The normal ear has the ability to distinguish separately 
a mixture of a considerable number of tones. The eye has no correspond- 
ing power a mixture of blue and yellow, for example, appears as a 
single color (green) and not as a combination of two colors. Fortunately, 
a very remarkable instrument, the spectroscope, separates a mixture of light 
into its component colors, or wave lengths, and enables the astronomer 
to determine precisely what wave lengths are present in the radiation 
from the sun, or, indeed, from any other celestial body from which 
sufficient radiant energy is received. . . . 

Of the ninety elements known on the earth, at least fifty have been found 
to exist in the atmosphere of the sun in the gaseous state, and the presence 
of several others is probable. The elements found in considerable abun- 
dance in the sun include hydrogen, helium, oxygen, magnesium, iron, 
silicon, sodium, potassium, calcium, aluminum, nickel, manganese, 
chromium, cobalt, titanium, copper, vanadium, and zinc. Some of the 
heaviest elements, such as gold and uranium, have not been found in the 
sun's atmosphere, perhaps because they lie at low levels. . . . 


As the sun rises, all the sparkling stars which sprinkle the clear night 
sky pale into insignificance and totally disappear. Yet actually they are suns, 
most of those which are visible to the unaided eye being much greater 
than our own. Indeed, some of them radiate thousands of times as much 
light, and a few are known which are millions of times greater in volume. 
Their apparent insignificance is due to their incomprehensibly enormous 

In order to bring within the range of our understanding the distance 
from the sun to the earth, we computed the time necessary for an 
imaginary skyship to travel from one of these bodies to the other at the rate 
of a thousand miles per hour. We found that if it continued on its way 
night and day, without pausing, it would require ten years and seven 
months to traverse the ninety-three million miles between the center of 
our system and this little planet of ours. Even with the aid of this calcula- 
tion we do not grasp the significance of the distances in the solar system. 


Perhaps we shall improve our understanding of the distances in the 
solar system by noting that the velocity we assumed for our skyship was 
more than 30 per cent greater than that of sound in our atmosphere, for 
sounds travels at the rate of only 736 miles per hour. Let us assume that 
sound could come from the sun to us at this speed. Then, if we should 
see some tremendous solar explosion and should expectantly await its 
thunders, we should be held in suspense before hearing *it for more than 
fourteen years. 

If we fail to comprehend the great distances between the members of 
our solar system, we naturally shall fall far short of grasping as realities 
the enormously greater distances to the stars. Yet we must attempt to do 
so, and we shall find that our understanding of these distances increases as 
we struggle with them. Let us start with the nearest star visible without 
optical aid from northern latitudes, the brilliant Sirius, the brightest 
star in all the sky. This beautiful bluish-white object is on the southern 
meridian at eight o'clock in the evening about the first of March each 
year. Astronomers have found by measurements that its distance is 51,700,- 
000,000,000 miles, or more than 550,000 times the distance from the sun to 
the earth. Therefore, more than 6,000,000 years would be required for 
our imaginary skyship to fly from the solar system to Sirius. 

In view of the enormous distances to even the nearest of the stars, we 
naturally wonder how astronomers have measured them and whether, 
after all, they are not merely conjectures resting upon no substantial 
foundation. The method of determining the distances of the relatively 
near stars is essentially the same as that used in determining the distance 
to the moon, namely, measuring the differences in their directions as seen 
from two different points. At some convenient time in the year the star 
Sirius, for example, is observed to be in a certain direction from the 
earth. A few months later, after the earth has moved many millions of 
miles in its orbit, Sirius is found to be in a slightly different direction. 
From this change in direction and the distance apart of the two points 
of observation the distance of Sirius is readily computed. Obviously, the 
method is entirely sound, and in the case of a star no more distant than 
Sirius it is known that the results are not uncertain to more than about 
one per cent of their value. 

Although the direct method of measuring stellar distances is relatively 
simple, the difficulties of putting it into effect are in general enormous be- 
cause of the remoteness of the stars. Indeed, the greatest observed differ- 
ence in direction of Sirius as observed from the earth from two points in 
its orbit separated by as great a distance as even that from the earth to the 
sun is extremely small. It is as small as the difference in direction of an 


object twenty-two miles away wher viewed first with one eye and then 
with the other. Moreover, only four or five other known stars, all of which 
except one are so faint as to be invisible without optical aid, are as near to 
us as Sirius. Indeed, all except a few hundred stars out of the millions 
which can be photographed through large telescopes are so very remote 
that their distances cannot be measured by the direct method which has 
been outlined. Nevertheless, our knowledge of the distances of the stars 
does not stop with this limited number, for astronomers with extraor- 
dinary skill have used their knowledge of the distances and other prop- 
erties of these nearer stars as a basis for several other methods which 
reach enormously farther into space. 

Before taking up the characteristics of the stars we shall define a more 
convenient unit for stellar distances which we shall often have occasion to 
use. It is the distance light travels in interstellar space in a year, known as 
the light-year. Since light travels in a vacuum at the rate of about 186,000 
miles per second, the light-year is 5,880,000,000,000 miles, or about 60,000 
times the distance from the sun to the earth. The star Sirius is distant 8.8 
light-years; the stars of the Big Dipper are distant 70 to 80 light-years; 
the Pleiades, about 200 light-years; the brighter stars in Orion, about 500 
light-years; and the star clouds which make up the Milky Way thousands 
of light-years. 

In spite of the enormous distances of the stars a great deal has been 
learned about them as individual bodies. In the first place, they consist 
of a number of classes depending upon the properties of the light they 
radiate as determined by the spectroscope. At one extreme are the blue 
Class B stars, of which a number of the brighter stars in Orion are exam- 
ples. These stars, which radiate many thousand times as much light as 
our sun, are enormous bodies whose exterior atmospheres are at tem- 
peratures ranging from 80,000 to 100,000 degrees Fahrenheit. In their 
atmospheres are spectral evidences of only hydrogen, helium, oxygen, and 

Next come the Class A stars, which are not quite so hot or brilliant as 
the Class B stars. Sirius is a splendid example of this class. Its surface 
temperature is nearly twice that of the sun, and it radiates twenty-seven 
times as much light. Then follow the Class F stars, of which Canopus and 
Procyon are illustrations. These stars approach in temperature, brilliance, 
and composition the Class G stars to which Capella and the sun belong. 
Nearly half of all the stars in the catalogues of stellar spectra are closely 
related to the sun. Only a few are giants of Class A, and a still smaller 
number are supergiants of Class B. 

Beyond the stars in the spectral sequence of class G, to which the *un 


belongs, come the cooler and ruddier stars of Class K, of which Arcturus 
and Aldebaran are notable examples. So far the stars of each spectral 
class connect by insensible gradations with those of the next class. But at 
the stars of Class K there is a discontinuity. The next class in the order 
in which they are usually given are those of Class M, of which Betelgeuse 
and Antares are examples. The atmospheres of these stars are at relatively 
low temperatures, as would naturally be inferred from their colors, and 
they contain many compounds as well as individual chemical elements. 
There are three other classes of stars, classes N, R, and S, which have no 
well-defined relationship to the other classes. They are all faint, with one 
or two exceptions being far beyond the range of the unaided eye, they 
are very few in number, and they are deep red in color. , . . 

In 1650, forty years after the invention of the telescope by Galileo, the 
star at the bend of the handle of the Big Dipper, which theretofore looked 
like an ordinary star, was found to consist of two stars apparently almost 
touching each other. It is now known, however, that these two stars are 
hundreds of times as far apart as are the earth and the sun. The discovery 
of this pair has been followed by the discovery of nearly 20,000 other 
double stars. Probably a few of these double pairs consist of two unrelated 
stars which happen to be for a time almost in the same direction from 
us, but in nearly all cases they are actually twin suns revolving around 
their center of gravity. The periods of revolution of most of them are so 
long, however, that they have not been determined from observations in 
the relatively short intervals since their discovery. . . . 

In certain cases the plane of revolution of a double star passes through or 
near the present position of the solar system. It is clear that when the two 
stars of such a pair are in a line with the earth, one wholly or partially 
eclipses the other, and at such times the light received from the pair is 
temporarily reduced. If the two stars are equal in volume and equally 
bright, the light received by the earth at the time of eclipse is one half 
its normal value. If one star is totally dark, it may entirely eclipse the 
luminous star. It is evident that many cases are theoretically possible, and 
it is an interesting fact that nearly all of them have been observed. 

It is clearly not difficult to determine the periods of revolution of these 
variable stars, as they are called, for their periods are defined by the inter- 
vals between their eclipses. But to determine the distance between the 
components of such a pair is quite another matter, for they are so close 
together that they appear to be a single star. Fortunately, a remarkable 
application of the spectroscope, which cannot be explained here, enables 
the astronomer to measure the relative velocity of a pair in their orbit; 


and from this velocity and the period of revolution of a pair he computes 
the perimeter of their orbit, and then their distance apart. . . . 

Many stars, however, are variables as a consequence of change in the 
rates of their radiation. In certain cases the variations in brightness are 
nearly as regular as those of eclipsing variables, though the changes are 
otherwise quite different. In other cases the variations in brightness are 
irregular and through wide ranges. For example, the star Omicron Ceti 
is at least ten thousand times brighter at its highest maxima than at its 
lowest minima. . . . 

The extreme limit in variable stars is reached by the temporary stars, 
or novae. These stars blaze out suddenly from obscurity to great brilliance, 
in some cases increasing their radiation a hundred-thousandfold in a day 
or two, only gradually to sink back to relative obscurity within a few 
months. A number of these remarkable temporary stars have played 
important roles in the history of astronomy. For example, the Greek 
philosopher and astronomer Hipparchus (about 160-105 B.C.) made the 
earliest known catalogue of stars, 1080 in number, in order to determine 
whether all stars are as transitory as the nova which he observed. Another 
temporary star inspired Tycho Brahe (1546-1601) to become an observer, 
and another which appeared in 1572 aroused the interest of Kepler in 

We do not know the cause of the remarkable outbursts of the novae, 
which are more violent phenomena on a stellar scale than any of the little 
explosions which ever take place on the earth or even than the much 
greater ones on the sun. If our sun should ever become a temporary star, 
our earth and the other planets would be quickly destroyed. It seems 
probable, however, that only certain stars are subject to these mighty 
outbursts, and that they occur again and again, separated by long intervals. 
These cataclysmic phenomena teach us how little we know of violent 
forces, even when we observe enormous volumes of incandescent gases 
shoot up hundreds of thousands of miles from the surface of the sun. 


There are among the stars many faint, hazy patches called nebulae, or 
little clouds. Some of them, such as that around the central star in the 
Sword of Orion, are faintly visible to the unaided eye, but most of them 
are found only with telescopic aid or by photography. They look like 
tenuous gaseous masses, and for a long time they were thought to be 
gaseous in nature, perhaps primordial world stuff out of which stars 
evolve in the course of enormous periods of time. With more powerful 
telescopes, however, a few of them were resolved into separate stars. 


Then for a time it was supposed that probably all nebulae are swarms 
of stars which can be resolved by sufficiently powerful instruments. But 
toward the close of the nineteenth century this conjecture was proved by 
the spectroscope to be false, for when their light was examined by this in- 
strument it was found to have the properties of light radiated by luminous 
gases rather than by relatively dense stars. Consequently, we now know 
that the nebulae, except those which are now classed differendy, are 
tenuous gases. . . . 


We have found that our earth is a member of a family of planets. Now 
we inquire whether our sun is similarly a member of a family of stars. 

When we attempt to determine whether the stars are the components 
of some vast organism, we are at once confronted with serious difficulties 
because of their great distances apart. For example, the distance between 
our solar system and the nearest known star, the far southern Alpha 
Centauri, is 4.3 light-years, or more than 25,000,000,000,000 miles. The 
nearest bright star visible from northern latitudes is Sirius at a distance 
of 8.8 light-years. Most of the stars within the range of the unaided eye 
are many times as far away as Sirius, while most of those photographed 
with large telescopes are distant more than a thousand light-years. . . . 

Let us first consider the stellar density near the present position of the 
solar system where the results are most trustworthy. Since it is possible 
with modern instruments and photographic processes to measure with 
much precision the distances of stars within thirteen light-years (76,000,- 
000,000,000 miles) of the sun, we shall first examine this region around 
the sun. Within this sphere of thirteen light-years in radius there are thirty 
known stars, five of which are doubles and one of which is a triple. It 
would be natural to expect that these relatively near stars would be in- 
cluded among the hundred brightest stars in the sky. As a matter of fact, 
only six of them, besides the sun, are bright enough to be visible without 
optical aid, while several of them are of such low luminosity that they are 
very faint in spite of their small distance from us, astronomically speaking. 
Since several of these near faint stars are of recent discovery, it is probable 
that there are a few others, at present unknown, which are within thirteen 
light-years of our sun. For the sake of having a definite number to serve 
as a basis for our calculations, we shall assume that there are thirty-five 
stars within this sphere. . . . 

It should not be understood that the thirty-five stars we are considering 
form a system in any special sense. They are simply a small sample out 
of an ocean of stars and give us some idea respecting what the general 


stellar system is like. At present the stars in this sphere arc near one 
another, but their neighborliness is only transitory, for they are moving in 
various directions at various velocities, and their mutual gravitation lacks 
much of being sufficient to hold them together. In a million years they 
will be far from one another and will have formed entirely different close 

There are, however, families of stars in the sense that they permanently, 
or at least for millions of millions of years, form a dynamical system of 
mutually interacting bodies. The best-known of such families is the 
Hyades stars in the constellation Taurus. About eighty of these stars are 
moving together through the celestial regions like a flock of migratory 
birds across the sky. Their spectra prove that they are similar in constitu- 
tion, they undoubtedly had a common origin, and they are undergoing 
parallel evolutions. . . . 

There are several hundred other known clusters of stars besides the 
Hyades family. Some of them are open groups like the Big Dipper and 
the Sickle in Leo. Others are more closely related families like the Pleiades, 
and in a few clusters the stars appear to be actually crowded together, 
although those which are nearest each other are rarely separated by less 
than a light-year. . . . 

Our sun does not appear to be a member of a compact (in the astronom- 
ical sense) family of stars, but it is a member of an enormous star cloud 
containing millions of stars. In these larger organizations the stars do 
not exhibit the similarities which are found among the stars of such 
compact families as the Hyades. Nor are they moving in parallel lines at 
the same speed. They consist, rather, of stars of all classes and kinds, 
moving around among one another somewhat like bees in a swarm, 
doubtless held loosely together by their mutual gravitation. These great 
star clouds largely make up the Milky Way. Even with the unaided eye 
they loom up conspicuously, under favorable conditions, in Cygnus, 
Sagittarius and Scorpius. With a photographic telescope their soft mist 
is resolved into myriads of stars. . . . 

When we pass beyond the star cloud of which the sun is a member, we 
arrive at our entire Milky Way system, or galaxy. It is composed of vast 
clouds of stars and millions of individual stars spread out in the form 
of a disk, the diameter of which is of the order of 60,000 light-years and 
the thickness of which is perhaps one eighth as great. It is not to be under- 
stood that our galaxy is homogeneous with well-defined exterior surfaces. 
It is, rather, a somewhat irregular assemblage of star clouds and individual 
stars, with vast regions of relatively high steller density, always decreasing, 
however, toward its borders. If the average stellar density of the galactic 


system were as great as it is within thirteen light-years of the sun, there 
would be in our galaxy more than 50,000,000,000 stars. Although this 
number may be somewhat too large, it is probable that there are several 
billion stars in our Milky Way system, and the number of them may 
exceed even fifty billions. It is interesting that heretofore estimates of 
astronomers have always fallen short of the actualities, as have conjectures 
in other fields of science. 

If the solar system were at the center of the galaxy, the stars would be 
symmetrically distributed around the Milky Way. The stars are, however, 
much more numerous in the direction of Sagittarius and Scorpius than in 
the opposite part of the heavens. This fact means that the galactic center 
is in the direction of these constellations, perhaps at a distance of a few 
thousand light-years. Moreover, the sun is some distance, perhaps a few 
hundred light-years, north of the central plane of the galaxy, a result 
which is inferred from the observed fact that stars are somewhat more 
numerous on the south side than they are on the north side of the great 
circle representing, at least generally, its central line. This is the position 
of the solar system at present, but the sun is moving obliquely northward 
from the galactic plane at the rate of a light-year in fifteen or twenty 
thousand years. Consequently, if it maintains its velocity and direction 
of motion for a million years, it will then be in a substantially different 
part of our galaxy. 

Our stellar system owes its disklike shape to its rotation, an inference 
which is based on dynamical principles and which has been verified by 
observations. Astronomers long ago proved the revolution of the earth 
around the sun by observations of the distant stars. Now they are proving 
the rotation of the enormous galaxy by measurements of velocities toward 
or from systems of stars far beyond its borders. ... In spite of all the 
variety in the motions of its stars and star clouds, it on the whole is 
involved in an immense gyration. At the distance of the sun from its 
center the velocity of its rotation is probably of the order of one or two 
hundred miles per second, and the period of its rotation between fifty and 
two hundred million years. It follows that during the long intervals of 
the geological eras our earth in its motion with the sun has traveled 
widely throughout our galactic system. . . . 


Somewhat outside of our galactic system, at distances ranging from 
25,000 to 160,000 light-years, there are approximately a hundred great 
aggregations of stars which are called globular dusters because they are 
almost exactly spherical in iorm. At the distances of these clusters only 


giant and supergiant stars are separately visible even through large tele- 
scopes. Consequently, those of their stars which are observed or photo- 
graphed as separate objects are only a very small fraction of all the stars 
which they contain. Yet the separately observed stars in the globular 
clusters are numbered by thousands and tens of thousands, and the fainter 
ones almost certainly number hundreds of thousands and probably 

One of the few globular clusters visible to the unaided eye is the Great 
Cluster in Hercules. At its distance of 33,000 light-years the combined 
light of 400,000 stars, each equal to our sun in luminosity, would be hardly 
visible to the unaided eye. Hence this cluster must be composed of an 
enormous number of stars and many of high luminosity. Indeed, on a 
photograph of it taken with one of the great telescopes on Mount Wilson, 
the images of 40,000 stars were counted, the faintest of these stars being 
approximately a hundred times as luminous as our sun. Consequently, 
there can be little doubt that this immense system contains at least a 
million stars as great as our sun, and probably many millions of lower 
luminosity. Yet it is so far away in the depths of space that we receive 
from all its millions of suns less than one sixth as much light as we 
receive from the North Star. 

. . . Assume that the Hercules cluster contains a hundred thousand 
giant and supergiant stars and a million stars altogether. We find from 
its distance and its apparent diameter that its actual diameter is about 
one hundred light-years. Hence it follows that if its hundred thousand 
great stars were uniformly distributed throughout its volume, the average 
distance between those which are adjacent would be more than two light- 
years, or about 140,000 times the distance from the sun to the earth. If 
we include the million stars in our computation, we find that the average 
distance between neighbors is about one light-year. . . . Even the giant 
stars in the clusters are no brighter as seen from one another than Venus 
is as observed from the earth. 

The globular clusters are dynamically mature; that is, they have 
arrived at a state in which as a whole they remain unchanged, although 
their individual stars are in ceaseless motion. Since many other aggre- 
gations of stars, such as our galaxy and its star clouds, are very irregular 
in structure, it does not seem probable that the globular clusters have 
always had their present perfect symmetries. Perhaps better support for 
our opinion that the stars in them were once irregularly distributed is 
found in the exterior galaxies which are usually, but not always, far from 

If the present nearly spherical forms of the globular clusters are due 


to dynamical evolutions, we may inquire how great must have been the 
interval o time between some earlier, heterogeneous state and their present 
conditions. We first find the astonishing result that the period of the 
circuit of a star around the Hercules cluster, or from near its exterior 
deep into its interior and out again somewhere else, is of the order of ten 
million years. We next note that the dynamical evolution which we are 
considering is due primarily to the near approaches of the stars, just as 
the uniform distribution of molecules of various kinds in a gas is due 
primarily to their collisions which occur with great frequency; indeed, 
on the average, five thousand million times a second. 

The distances between the stars in the clusters are so great that, on the 
average, a star will make ten thousand circuits before it will pass near 
enough another star to have the direction of its motion changed by as 
much as twenty degrees. That is, on the average it moves for a hundred 
thousand million years (ten thousand times ten million years) as though 
the mass of the cluster were not concentrated into stars. Then it passes so 
near one of these concentrations of mass (one of the stars) that the 
direction of its motion is appreciably changed. After a very large number, 
perhaps a million, of these adventures all the earlier heterogeneities are 
smoothed out with a resulting globular cluster of stars. That is, the very 
organization of the globular clusters proves that these spherical masses 
of stars have been undergoing independent evolutions for at least millions 
of millions of years. In the course of time, however, these symmetrical 
structures may pass near or through somewhat similar aggregations and 
be transformed into spinning irregular spirals similar to our galaxy, 


We have often called the Milky Way system of stars "our" galaxy, as 
though it were something we possess, or which is at least in our immediate 
neighborhood. From the standpoint of the earth or even of the whole solar 
system our language has been presumptuous, for we have explored tens 
of thousands of light-years, or hundreds of millions of times the distance 
from our planet to the sun. . . . But all these objects are of secondary 
importance and interest in comparison with the enormous galaxy known 
as the Great Nebula in Andromeda. Until within a few years astronomers 
gazed up at this hazy patch of light, which is just within the range of 
the unaided eye, and thought they were looking only at a tenuous nebula 
lying out toward the borders of our stellar system. Now they know that 
what they have been seeing is a great exterior galaxy, which in magnitude, 
in number of stars, and in structure is similar to our own. 

The distance from our present position to the Great Nebula in An- 


dromeda is about 900,000 light-years. Consequently, we see this galaxy 
not as it is now but as it was before our ancestors evolved to the level 
of men. . . . The so-called Andromeda nebula is actually a galaxy in 
every essential respect similar to our own, a much flattened disk of many 
billions of stars, having a diameter of something like 80,000 light-years 
and rotating in a period of perhaps 150,000,000 years. 

There are within a million light-years of the solar system six known 
galaxies, including our own. But outside of this great sphere there are 
hundreds of thousands of other galaxies within easy reach of large photo- 
graphic telescopes. . . . 

From atoms to galaxies each physical unit is made up of smaller units 
atoms of protons and electrons, molecules of atoms, stars of molecules, 
galaxies of stars. We naturally inquire whether the galaxies we observe 
are not components of still greater cosmic units; whether our Milky Way 
system, for example, the Magellanic Clouds, the Andromeda galaxy and 
others which are relatively near are not the constituents of a supergalaxy 
enormously greater than any one of them, and perhaps millions of light- 
years in diameter. Although the field which we are considering is rela- 
tively new, astronomers have already found numerous aggregations of 
galaxies into supergalaxies. For example, Harlow Shapley has described 
a supergalaxy in the direction of Centaurus, but a hundred and fifty 
million light-years beyond the stars of this constellation, which is com- 
posed of more than three hundred galaxies, all of which are probably 
comparable to our own steller system. The space occupied by this super- 
galaxy is an oval about seven million light-years in length and two million 
light-years in diameter. It is so vast that the average distance between 
those of its galaxies which are adjacent is approximately a million light- 

What is beyond the supergalaxies? There is no observational evidence 
bearing upon the question. There are good theoretical reasons, however, 
for concluding that they do not extend on through an infinite space with 
the approximate frequency which is found within a few hundred million 
light-years of our own galaxy. According to certain deductions from the 
theory of relativity they are limited in number, and space itself is limited 
in extent. On the other hand, the supergalaxies which we now know 
may be the component units of enormously greater supergalaxies of the 
second order. And these supergalaxies of the second order may be the 
constituents of supergalaxies of the third order, and so on upward in an 
unending sequence. And, just as molecules are composed of atoms, and 
atoms of protons and electrons, so protons and electrons may be made up 


of still smaller units, and so on downward in an unending sequence of 

Naturally, it is unsafe to draw any positive conclusions respecting super- 
galaxies of higher order or respecting subelectrons, for direct evidence 
is lacking and we can reason only by analogy. It is even more hazardous 
to speculate regarding a creation of the physical universe, for observa- 
tional evidence is equally lacking, and there is not even analogy as a 
guide. Consequently, though science has placed us on an eminence from 
which we see very far, beyond our horizon there still lies a challenging 

Is There Life on Other Worlds? 


*^ center of the universe the question of life on other worlds could 
hardly arise; there were no other worlds in the astronomical sense, although 
a heaven above and a hell beneath might form adjuncts to this world. 
The cosmology of the Divina Commedia is typical of its period. In 1440 
we find Nicholas of Cusa comparing our earth, as Pythagoras had done 
before him, to the other stars, although without expressing any opinion as 
to whether these other stars were inhabited or not. At the end of the next 
century Giordano Bruno wrote that "there are endless particular worlds 
similar to this of the earth." He plainly supposed these other worlds "the 
moon, planets and other stars, which are infinite in number" to be 
inhabited, since he regarded their creation as evidence of the Divine 
goodness. He was burned at the stake in 1600; had he lived only ten years 
longer, his convictions would have been strengthened by Galileo's discovery 
of mountains and supposed seas on the moon. 
The arguments of Kepler and Newton led to a general recognition that 


the stars were not other worlds like our earth but other suns like our sun. 
When once this was accepted it became natural to imagine that they also 
were surrounded by planets and to picture each sun as showering life-sus- 
taining light and heat on inhabitants more or less like ourselves. In 1829 
a New York newspaper scored a great journalistic hit by giving a vivid, 
but wholly fictitious, account of the activities of the inhabitants of the 
moon as seen through the telescope recently erected by His Majesty's 
Government at the Cape. 

It would be a long time before we could see what the New York paper 
claimed to see on the moon batlike men flying through the air and 
inhabiting houses in trees even if it were there to see. To see an object 
of human size on the moon in detail we should need a telescope of from 
10,000 to a 100,000 inches aperture, and even then we should have to wait 
years, or more probably centuries, before the air was still and clear enough 
for us to see details of human size. 

To detect general evidence of life on even the nearest of the planets 
would demand far larger telescopes than anything at present in existence, 
unless this evidence occupied an appreciable fraction of the planet's surface. 
The French astronomer Flammarion once suggested that if chains of light 
were placed on the Sahara on a sufficiently generous scale, they might be 
visible to Martian astronomers if any such there be. If this light were 
placed so as to form a mathematical pattern, intelligent Martians might 
conjecture that there was intelligent life on earth. Flammarion thought 
that the lights might suitably be arranged to illustrate the theorem of 
Pythagoras (Euclid, i. 47). Possibly a better scheme would be a group of 
searchlights which could emit successive flashes to represent a series of 
numbers. If, for instance, the numbers 3, 5, 7, n, 13, 17, 19, 23 ... (the 
sequence of primes) were transmitted, the Martians might surely infer the 
existence of intelligent Tellurians. But any visual communication between 
planets would need a combination of high telescopic power at one end 
and of engineering works on a colossal, although not impossible, scale at 
the other. 

Some astronomers mainly in the past have thought that the so-called 
canals on Mars provided evidence of just this kind, although of course 
unintentionally on the part of the Martians. Two white patches which 
surround the two poles of Mars are observed to increase and decrease with 
the seasons, like our terrestrial polar ice. Over the surface of Mars some 
astronomers have claimed to see a geometrical network of straight lines, 
which they have interpreted as a system of irrigation canals, designed to 
bring melted ice from these polar caps to parched equatorial regions. 
Percival Lowell calculated that this could be done by a pumping system 


of 4,000 times the power of Niagara. It is fairly certain now that the polar 
caps are not of ice, but even if they were, the radiation of the summer sun 
on Mars is so feeble that it could not melt more than a very thin layer of 
ice before the winter cold came to freeze it solid again. Actually the caps 
are observed to change very rapidly and are most probably clouds con- 
sisting of some kind of solid particles. 

The alleged canals cannot be seen at all in the largest telescopes nor 
can they be photographed, but there are technical reasons why neither of 
these considerations is conclusive against the existence of the canals. A 
variety of evidence suggests, however, that the canals are mere subjective 
illusions the result of overstraining the eyes in trying to see every detail 
of a never very brightly illuminated surface. Experiments with school chil- 
dren have shown that under such circumstances the strained eye tends to 
connect patches of color by straight lines. This will at least explain why 
various astronomers have claimed to see straight lines not only on Mars, 
where it is just conceivable that there might be canals, but also on Mercury 
and the largest satellite of Jupiter, where it seems beyond the bounds of 
possibility that canals could have been constructed, as well as on Venus, on 
which real canals could not possibly be seen since its solid surface is entirely 
hidden under clouds. It may be significant that E. E. Barnard, perhaps the 
most skilled observer that astronomy has ever known, was never able to 
see the canals at all, although he studied Mars for years through the largest 

A more promising line of approach to our problem is to examine which, 
if any, of the planets is physically suitable for life. But we are at once con- 
fronted with the difficulty that we do not know what precise conditions 
are necessary for life. A human being transferred to the surface of any 
one of the planets or of their satellites, would die at once, and this for 
several different reasons on each. On Jupiter he would be simultaneously 
frozen, asphyxiated, and poisoned, as well as doubly pressed to death by 
his own weight and by an atmospheric pressure of about a million terres- 
trial atmospheres. On Mercury he would be burned to death by the sun's 
heat, killed by its ultra-violet radiation, asphyxiated from want of oxygen, 
and desiccated from want of water. But this does not touch the question 
of whether other planets may not have developed species of life suited to 
their own physical conditions. When we think of the vast variety of con- 
ditions under which terrestrial life exists on earth plankton, soil bacteria, 
stone bacteria, and the great variety of bacteria which are parasitic on the 
higher forms of life it would seem rash to suggest that there are any 
physical conditions whatever to which life cannot adapt itself. Yet as the 
physical states of other planets are so different from that of our own, it 


seems safe to say that any life there may be on any of them must be very 
different from the life on earth. 

The visible surface of Jupiter has a temperature of about 138 C, 
which represents about 248 degrees of frost on the Fahrenheit scale. The 
planet probably comprises an inner core of rock, with a surrounding layer 
of ice some 16,000 miles in thickness, and an atmosphere which again is 
several thousands of miles thick and exerts the pressure of a million 
terrestrial atmospheres which we have already mentioned. The only known 
constituents of this atmosphere are the poisonous gases methane and 
ammonia. It is certainly hard to imagine such a planet providing a home 
for life of any kind whatever. The planets Saturn, Uranus, Neptune, and 
Pluto, being farther from the sun, are almost certainly even colder than 
Jupiter and in all probability suffer from at least equal disabilities as 
abodes of life. 

Turning sunward from these dismal planets, we come first to Mars, 
where we find conditions much more like those of our own planet. The 
average temperature is about 40 C., which is also 40 on the Fahren- 
heit scale, but the temperature rises above the freezing point on summer 
afternoons in the equatorial regions. The atmosphere contains at most 
only small amounts of oxygen and carbon dioxide, perhaps none at all, so 
that there can be no vegetation comparable with that of the earth. The 
surface, in so far as it can be tested by a study of its powers of reflection 
and polarization, appears to consist of lava and volcanic ash. To us it may 
not seem a promising or comfortable home for life, but life of some kind 
or other may be there nevertheless. 

Being at the same average distance from the sun as the earth, the moon 
has about the same average temperature, but the variations around this 
average temperature are enormous, the equatorial temperature varying 
roughly from 120 C. to 80 C. The telescope shows high ranges of 
mountains, apparently volcanic, interspersed with flat plains of volcanic 
ash. The moon has no atmosphere and consequently no water; it shows 
no signs of life or change of any kind, unless perhaps for rare falls of 
rock such as might result from the impact of meteors falling in from outer 
space. A small town on the moon, perhaps even a large building, ought to 
be visible in our largest telescopes, but, needless to say, we see nothing of 
the kind. 

Venus, the planet next to the earth, presents an interesting problem. 
It is similar to the earth in size but being nearer the sun is somewhat 
warmer. As it is blanketed in cloud we can only guess as to the nature of 
its surface. But its atmosphere can be studied and is found to contain 
little or no oxygen, so that the planet's surface can hardly be covered with 


vegetation as the surface of the earth is. Indeed, its surface is probably so 
hot that water would boil away. Yet no trace of water vapor is found in 
the atmosphere, so that the planet may well be devoid of water. There are 
reasons for thinking that its shroud of clouds may consist of solid par- 
ticles, possibly hydrates of formaldehyde. Clearly any life that this planet 
may harbor must be very different from that of the earth. 

The only planet that remains is Mercury. This always turns the same 
face to the sun and its temperature ranges from about 420 C. at the center 
of this face to unimaginable depths of cold in the eternal night of the face 
which never sees the sun. The planet is too feeble gravitationally to retain 
much of an atmosphere and its surface, in so far as this can be tested, 
appears to consist mainly of volcanic ash like the moon and Mars. Once 
again we have a planet which does not appear promising as an abode of 
life and any life that there may be must be very different from our own. 

Thus our survey of the solar system forces us to the conclusion that it 
contains no place other than our earth which is at all suitable for life at 
all resembling that existing on earth. The other planets are ruled out 
largely by unsuitable temperatures. It used to be thought that Mars might 
have had a temperature more suited to life in some past epoch when the 
sun's radiation was more energetic than it now is, and that similarly 
Venus can perhaps look forward to a more temperate climate in some 
future age. But these possibilities hardly accord with modern views of 
stellar evolution. The sun is now thought to be a comparatively unchanging 
structure, which has radiated much as now through the greater part of its 
past life and will continue to do the same until it changes cataclysmically 
into a minute "white dwarf" star. When this happens there will be a fall 
of temperature too rapid for life to survive anywhere in the solar system 
and too great for new life ever to get a foothold. As regards suitability for 
life, the earth seems permanently to hold a unique position among the 
bodies surrounding our sun. 

Our sun is, however, only one of myriads of stars in space. Our own 
galaxy alone contains about 100,000 million stars, and there are perhaps 
10,000 million similar galaxies in space. Stars are about as numerous in 
space as grains of sand in the Sahara. What can we say about the possibili- 
ties of life on planets surrounding these other suns ? 

We want first to know whether these planets exist. Observational astron- 
omy can tell us nothing; if every star in the sky were surrounded by a 
planetary system like that of our sun, no telescope on earth could reveal a 
single one of these planets. Theory can tell us a little more. While there 
is some doubt as to the exact manner in which the sun acquired its family 
of planets, all modern theories are at one in supposing that it was the 


result of the close approach of another star. Other stars in the sky must 
also experience similar approaches, although calculation shows that such 
events must be excessively rare. Under conditions like those which now 
prevail in the neighborhood of the sun, a star will experience an approach 
close enough to generate planets only about once in every million million 
million years. If we suppose the star to have lived under these conditions 
for about 2,000 million years, only one star in 500 million will have expe- 
rienced the necessary close encounter, so that at most one star in 500 
million will be surrounded by planets. This looks an absurdly minute 
fraction of the whole, yet when the whole consists of a thousand million 
million million stars, this minute fraction represents two million million 
stars. On this calculation, then two million million stars must already be 
surrounded by planets and a new solar system is born every few hours. 
The calculation probably needs many adjustments; for instance, condi- 
tions near our sun are not necessarily typical of conditions throughout 
space and the conditions of today are probably not typical of conditions in 
past ages. Indeed, on any reasonable view of stellar evolution, each star 
must have begun its life as a vast mass of nebulous gas, in which state it 
would present a far more vulnerable target than now for disruptive attacks 
by other stars. Detailed calculation shows that the chance of a star's 
producing planets in this early stage, although not large, would be quite 
considerable, and suggests, with a large margin to spare, that although 
planetary systems may be rare in space, their total number is far from 
insignificant. Out of the thousands or millions of millions of planets that 
there must surely be in space, a very great number must have physical 
conditions very similar to those prevailing on earth. 

We cannot even guess whether these are inhabited by life like our own 
or by life of any kind whatever. The same chemical atoms exist there as 
exist here and must have the same properties, so that it is likely that the 
same inorganic compounds have formed there as have formed here. If so, 
we would like to know how far the chain of life has progressed, but 
present-day science can give no help. We can only wonder whether any 
life there may be elsewhere in the universe has succeeded in managing it* 
affairs better than we have done in recent years. 


The Milky Way ana Beyond 


begins his lecture with the words "Gentlemen, you have seen the moon 
or at least heard tell of it." I think I may in the same way presume that 
you are acquainted with the Milky Way, which can be seen on any clear 
dark night as a faintly luminous band forming an arch from horizon to 
horizon. The telescopes show that it is composed of multitudes of stars. 
One is tempted to say "countless multitudes"; but it is part of the business 
of an astronomer to count them, and the number is not uncountable 
though it amounts to more than ten thousand millions. The number 
of stars in the Milky Way is considerably greater than the number of 
human beings on the earth. Each star, I may remind you, is an immense 
fiery globe of the same general nature as our sun. 

There is no sharp division between the distant stars which form the 
Milky Way and the brighter stars which we see strewn over the sky. 
All these stars taken together form one system or galaxy; its extent is 
enormous but not unlimited. Since we are situated inside it we do not 
obtain a good view of its form; but we are able to see far away in space 
other galaxies which also consist of thousands of millions of stars, and 
presumably if we could see our own galaxy from outside, it would appear 
like one of them. These other galaxies are known as "spiral nebulae." 
We believe that our own Milky Way system is more or less like them. If so, 
the stars form a flat coil rather like a watch-spring except that the coil 
is double. 

When we look out in directions perpendicular to the plane of the 
coil, we soon reach the limit of the system; but in the plane of the coil 
we see stars behind stars until they become indistinguishable and fade 
into the hazy light of the Milky Way. It has been ascertained that we 
are a very long way from the centre of our own galaxy, so that there are 
many more stars on one side of us than on the other. 



Looking at one of these galaxies, it is impossible to resist the impression 
that it is whirling round like a Catherine Wheel. It has, in fact, been 
possible to prove that some of the spiral nebulae are rotating, and to 
measure the rate of rotation. Also by studying the motions of the stars in 
our own galaxy, it has been found that it too is rotating about a centre. 
The centre is situated a long way from us in the constellation Ophiuchus 
near a particularly bright patch of the Milky Way; the actual centre is, 
however, hidden from us by a cloud of obscuring matter. My phrase, 
"whirling round," may possibly give you a wrong impression. With these 
vast systems we have to think in a different scale of space and time, and 
the whirling is slow according to our ordinary ideas. It takes about 300 
million years for the Milky Way to turn round once. But after all that is 
not so very long. Geologists tell us that the older rocks in the earth's 
crust were formed 1300 million years ago; so the sun, carrying with it the 
earth and planets, has made four or five complete revolutions round the 
centre of the galaxy within geological times. 

The stars which form our Milky Way system show a very wide diver- 
sity. Some give out more than 10,000 times as much light and heat as 
the sun; others less than i/iooth. Some are extremely dense and com- 
pact; others are extremely tenuous. Some have a surface temperature as 
high as 20,000 or 30,000 C.; others not more than 3000 C. Some are 
believed to be pulsating swelling up and deflating within a period of a 
few days or weeks; these undergo great changes of light and heat accom- 
panying the expansion and collapse. It would be awkward for us if our 
sun behaved that way. A considerable proportion (about 1/3 of the whole 
number) go about in pairs, forming "double stars"; the majority, how- 
ever, are bachelors like the sun. 

But in spite of this diversity, the stars have one comparatively uniform 
characteristic, namely their mass, that is, the amount of matter which 
goes to form them. A range from 1/5 to 5 times the sun's mass would 
cover all but the most exceptional stars; and the general run of the masses 
is within an even narrower range. Among a hundred stars picked at 
random the diversity of mass would not be greater proportionately than 
among a hundred men, women and children picked at random from a 

Broadly speaking, a big star is big, not because it contains an excessive 
amount of material, but because it is puffed out like a balloon; and a 
small star is small because its material is highly compressed. Our sun, 
which is intermediate in this, as in most respects, has a density rather 
greater than that of water. (The sun is in every way a typical middle-class 
star.) The two extremesthe extremely rarefied and the extremely dense 


stars are especially interesting. We find stars whose material is as tenuous 
as a gas. The well-known star Capella, for example, has an average density 
about equal to that of air; to be inside Capella would be like being 
surrounded by air, as we ordinarily are, except that the temperature 
(which is about 5,000,000 C) is hotter than we are accustomed to. Still 
more extreme are the red giant stars Betelgeuse in Orion and Antares in 
Scorpio. To obtain a star like Betelgeuse, we must imagine the sun swell- 
ing out until it has swallowed up Mercury, Venus and the Earth, and 
has a circumference almost equal to the orbit of Mars. The density of 
this vast globe is that of a gas in a rather highly exhausted vessel. Betel- 
geuse could be described as "a rather good vacuum." 

At the other extreme are the "white dwarf stars, which have extrava- 
gantly high density. I must say a little about the way in which this was 

Between 1916 and 1924 I was very much occupied trying to understand 
the internal constitution of the stars, for example, finding the temperature 
in the deep interior, which is usually ten million degrees, and making out 
what sort of properties matter would have at such high temperatures. 
Physicists had recently been making great advances in our knowledge of 
atoms and radiation; and the problem was to apply this new knowledge 
to the study of what was taking place inside a star. In the end I obtained 
a formula by which, if you knew the mass of a star, you could calculate 
how bright it ought to be. An electrical engineer will tell you that to 
produce a certain amount of illumination you must have a dynamo of a 
size which he will specify; somewhat analogously I found that for a star 
to give a certain amount of illumination it must have a definite mass 
which the formula specified. This formula, however, was not intended 
to apply to all stars, but only to diffuse stars with densities corresponding 
to a gas, because the problem became too complicated if the material 
could not be treated as a perfect gas. 

Having obtained the theoretical formula, the next thing was to compare 
it with observation. That is where the trouble often begins. And there 
was trouble in this case; only it was not of the usual kind. The observed 
masses and luminosities agreed with the formulae all right; the trouble 
was that they would not stop agreeing! The dense stars for which the 
formula was not intended agreed just as well as the diffuse stars for 
which the formula was intended. This surprising result could only mean 
that, although their densities were as great as that of water or iron, the 
stellar material was nevertheless behaving like a gas; in particular, it 
was compressible like an ordinary gas. 

We had been rather blind not to have foreseen this. Why is it that we 


can compress air, but cannot appreciably compress water? It is because 
in air the ultimate particles (the molecules) are wide apart, with plenty 
of empty space between them. When we compress air we merely pack 
the molecules a bit closer, reducing the amount of vacant space. But in 
water the molecules are practically in contact and cannot be packed any 
closer. In all substances the ordinary limit of compression is when the 
molecules jam in contact; after that we cannot appreciably increase the 
density. This limit corresponds approximately to the density of the solid 
or liquid state. We had been supposing that the same limit would apply 
in the interior of a star. We ought to have remembered that at the temper- 
ature of millions of degrees there prevailing the atoms are highly ionized, 
i.e. broken up. An atom has a heavy central nucleus surrounded by a 
widely extended but insubstantial structure of electrons a sort of 
crinoline. At the high temperature in the stars this crinoline of electrons 
is broken up. If you are calculating how many dancers can be accom- 
modated in a ball-room, it makes a difference whether the ladies wear 
crinolines or not. Judging by the crinolined terrestrial atoms we should 
reach the limit of compression at densities not much greater than water; 
but the uncrinolined stellar atoms can pack much more densely, and do 
not jam together until densities far beyond terrestrial experience are 

This suggested that there might exist stars of density greater than any 
material hitherto known, which called to mind a mystery concerning the 
Companion of Sirius. The dog-star Sirius has a faint companion close 
to it, visible in telescopes of moderate power. There is a method of finding 
densities of stars which I must not stop to explain. The method is rather 
tentative; and when it was found to give for the Companion of Sirius 
a density 50,000 times greater than water, it was naturally assumed that 
it had gone wrong in its application. But in the light of the foregoing 
discussion, it now seemed possible that the method had not failed, and 
that the extravagantly high density might be genuine. So astronomers 
endeavoured to check the determination of density by another method 
depending on Einstein's relativity theory. The second method confirmed 
the high density, and it is now generally accepted. The stuff of the 
Companion of Sirius is 2000 times as dense as platinum. Imagine a 
match-box filled with this matter. It would need a crane to lift it it 
would weigh a ton. 

I am afraid that what I have to say about the stars is largely a matter 
of facts and figures. There is only one star near enough for us to study 
its surface, namely our sun. Ordinary photographs of the sun show few 
features, except the dark spots which appear at times. But much more 


interesting photographs are obtained by using a spectro-heliograph, which 
is an instrument blind to all light except that of one particular wave 
length coming from one particular kind of atom. 

Now let us turn to the rest of the universe which lies beyond the Milky 
Way. Our galaxy is, as it were, an oasis of matter in the desert of empti- 
ness, an island in the boundless ocean of space. From our own island we 
see in the far distance other islands in fact a whole archipelago of 
islands one beyond another till our vision fails. One of the nearest of 
diem can actually be seen with the naked eye; it is in the constellation 
Andromeda, and looks like a faint, rather hazy, star. The light which 
we now see has taken 900,000 years to reach us. When we look at that 
faint object in Andromeda we are looking back 900,000 years into the 
past. Some of the telescopic spiral nebulae are much more distant. The 
most remote that has yet been examined is 300,000,000 light-years away. 

These galaxies are very numerous. From sample counts it is found 
that more than a million of them are visible in our largest telescopes; and 
there must be many more fainter ones which we do not see. Our sun 
is just one star in a system of thousands of millions of stars; and that 
whole system is just one galaxy in a universe of thousands of millions 
of galaxies. 

Let us pause to see where we have now got to in the scale of size. The 
following comparative table of distances will help to show us where we 


Distance of the sun 150,000,000 

Limit of the solar system (Orbit of Pluto) .... 5,800,000,000 

Distance of the nearest star 40,000,000,000,000 

Distance of nearest external galaxy 8,000,000,000,000,000,000 

Distance of furthest galaxy yet observed .... 3,000,000,000,000,000,000,000 

Some people complain that they cannot realize these figures. Of course 
they cannot. But that is the last thing one wants to do with big numbers 
to "realize" them. In a few weeks time our finance minister in England 
will be presenting his annual budget of about ^900,000,000. Do you sup- 
pose that by way of preparation, he throws himself into a state of trance in 
which he can visualize the vast pile of coins or notes or commodities 
that it represents? I am quite sure he cannot "realize" ^900,000,000. But 
he can spend it. It is a fallacious idea that these big numbers create a 
difficulty in comprehending astronomy; they can only do so if you are 
seeking the wrong sort of comprehension. They are not meant to be 
gaped at, but to be manipulated and used. It is as easy to use millions 


and billions and trillions for our counters as ones and twos and threes. 
What I want to call attention to in the above table is that since we are 
going out beyond the Milky Way we have taken a very big step up in 
the scale of distance. 

The remarkable thing that has been discovered about these galaxies 
is that (except three or four of the nearest of them) they are running 
away from our own galaxy; and the further they are away, the faster they 
go. The distant ones have very high speeds. On the average the speed 
is proportional to the distance, so that a galaxy 10 million light-years 
away recedes at 1500 kilometres per second, one 50 million light-years 
away recedes at 7500 kilometres per second, and so on. The fastest yet 
discovered recedes at 42,000 kilometres per second. 

Why are they all running away from us ? If we think a little, we shall 
see that the aversion is not especially directed against us; they are running 
away from us, but they are also running away from each other. If this 
room were to expand 10 per cent in its dimensions, the seats all separating 
in proportion, you would at first think that everyone was moving away 
from you; the man 10 metres away has moved i metre further off; the 
man 20 metres away has moved 2 metres further off; and so on. Just 
as with the galaxies, the recession is proportional to the distance. This 
law of proportion is characteristic of a uniform expansion, not directed 
away from any one centre, but causing a general scattering apart. So we 
conclude that recession of the nebulae is an eflect of uniform expansion. 

The system of the galaxies is all the universe we know, and indeed 
we have strong reason to believe that it is the whole physical universe. 
The expansion of the system, or scattering apart of the galaxies, is there- 
fore commonly referred to as the expansion of the universe; and the 
problem which it raises is the problem of the "expanding universe." 

The expansion is proceeding so fast that, at the present rate, the nebulae 
will recede to double their present distances in 1300 million years. Astron- 
omers will have to double the apertures of their telescopes every 1300 
million years in order to keep pace with the recession. But seriously 1300 
million years is not a long period of cosmic history; I have already men- 
tioned it as the age of terrestrial rocks. It comes as a surprise that the 
universe should have doubled its dimensions within geological times. 
It means that we cannot go back indefinitely in time; and indeed the 
enormous time-scale of billions [The English "billion" is equivalent to 
the American "trillion."] of years, which was fashionable ten years ago, 
must be drastically cut down. We are becoming reconciled to this speed- 
ing up of the time-scale of evolution, for various other lines of evidence 
have convinced us that it is essential. It seems clear now that we must 


take an upper limit to the age of the stars not greater than 10,000 million 
years; previously, an age of a thousand times longer was commonly 

For reasons which I cannot discuss fully we believe that along with 
the expansion of the material universe there is an expansion of space 
itself. The idea is that the island galaxies are scattered throughout a 
"spherical space." Spherical space means that if you keep going straight 
on in any direction you will ultimately find yourself back at your starting 
point. This is analogous to what happens when you travel straight ahead 
on the earth; you reach your starting point again, having gone round the 
world. But here we apply the analogy to an extra dimension to space 
instead of to a surface. I realize, of course, that this conception of a 
closed spherical space is very difficult to grasp, but really it is not worse 
than the older conception of infinite open space which no one can properly 
imagine. No one can conceive infinity; one just uses the term by habit 
without trying to grasp it. If I may refer to our English expression, "out 
of the frying-pan into the fire," I suggest that if you feel that in receiving 
this modern conception of space you are falling into the fire, please 
remember that you are at least escaping from the frying-pan. 

Spherical space has many curious properties. I said that if you go 
straight ahead in any direction you will return to your starting point. So 
if you look far enough in any direction and there is nothing in the way, 
you ought to see the back of your head. Well, not exactly because 
light takes at least 6000 million years to travel round the universe and 
your head was not there when it started. But you will understand the 
general idea. However, these curiosities do not concern us much. The 
main point is that if the galaxies are distributed over the spherical space 
more or less in the same way that human beings are distributed over the 
earth, they cannot form an expanding system they cannot all be receding 
from one another unless the space itself expands. So the expansion of 
the material system involves, and is an aspect of, an expansion of space. 

This scattering apart of the galaxies was not unforeseen. As far back 
as 1917, Professor W. de Sitter showed that there was reason to expect 
this phenomenon and urged astronomers to look for it. But it is only 
recently that radial velocities of spiral nebulae have been measured in 
sufficient numbers to show conclusively that the scattering occurs. It is 
one of the deductions from relativity theory that there must exist a force, 
known as "cosmical repulsion," which tends to produce this kind of 
scattering in which every object recedes from every other object. You 
know the theory of relativity led to certain astronomical consequences 
a bending of light near the sun detectable at eclipses, a motion of the 


perihelion of Mercury, a red-shift of spectral lines which have been 
more or less satisfactorily verified. The existence of cosmical repulsion 
is an equally definite consequence of the theory, though this is not so 
widely known partly because it comes from a more difficult branch of 
the theory and was not noticed so early, and perhaps partly because it is 
not so directly associated with the magic name of Einstein. 

I can see no reason to doubt that the observed recession of the spiral 
nebulae is due to cosmical repulsion, and is the effect predicted by 
relativity theory which we were hoping to find. Many other explanations 
have been proposed some of them rather fantastic and there has been 
a great deal of discussion which seems to me rather pointless. In this, as 
in other developments of scientific exploration, we must recognize the 
limitations of our present knowledge and be prepared to consider revolu- 
tionary changes. But when, as in this case, observation agrees with what 
our existing knowledge had led us to expect, it is reasonable to feel 
encouraged to pursue the line of thought which has proved successful; 
and there seems little excuse for an outburst of unsupported speculation. 

. , , Now we have been all over the universe. If my survey has been 
rather inadequate, I might plead that light takes 6000 million years to 
make the circuit that I have made in an hour. Or rather, that was the 
original length of the circuit; but the universe is expanding continually, 
and whilst I have been talking the increase of the circuit amounts to one 
or two more days' journey for the light. Anyhow, the time has come to 
leave this nightmare of immensity and find again, among the myriads 
of orbs, the tiny planet which is our home. 



A Young Man Looking at Rocks 



From The Old Red Sandstone 

bettering their circumstances, and adding to the amount of their 
enjoyment, is a very simple one. Do not seek happiness in what is mis- 
named pleasure; seek it rather in what is termed study. Keep your con- 
sciences clear, your curiosity fresh, and embrace every opportunity of 
cultivating your minds. You will gain nothing by attending Chartist 
meetings. The fellows who speak nonsense with fluency at these assem- 
blies, and deem their nonsense eloquence, are totally unable to help either 
you or themselves : or, if they do succeed in helping themselves, it will be 
all at your expense. Leave them to harangue unheeded, and set yourselves 
to occupy your leisure hours in making yourselves wiser men. Learn to 
make a right use of your eyes; the commonest things are worth looking 
at even stones and weeds, and the most familiar animals. 

It was twenty years last February since I set out, a little before sunrise 
to make my first acquaintance with a life of labour and restraint: and I 
have rarely had a heavier heart than on that morning. I was but a slim, 
loose-jointed boy at the time, fond of the pretty intangibilities of romance, 
and of dreaming when broad awake; and, woeful change! I was now 
going to work at what Burns has instanced, in his "Twa Dogs" as one of 
the most disagreeable of all employments, to work in a quarry. Bating 
the passing uneasiness occasioned by a few gloomy anticipations, the 
portion of my life which had already gone by had been happy beyond the 
common lot. I had been a wanderer among rocks and woods, a reader of 
curious books when I could get them, a gleaner of old traditionary stories: 
and now I was going to exchange all my day-dreams, and all my amuse- 



ments, for the kind of life in which men toil every day that they may be 
enabled to eat, and eat every day that they may be enabled to toil! 

The quarry in which I wrought lay on the southern shore of a noble 
inland bay, or frith rather, with a little clear stream on the one side, 
and a thick fir wood on the other. It had been opened in the Old Red 
Sandstone of the district, and was overtopped by a huge bank of diluvial 
clay, which rose over it in some places to the height of nearly thirty feet, 
and which at this time was rent and shivered, wherever it presented an 
open front to the weather, by a recent frost. A heap of loose fragments, 
which had fallen from above, blocked up the face of the quarry, and my 
first employment was to clear them away. The friction of the shovel 
soon blistered my hands, but the pain was by no means very severe, and I 
wrought hard and willingly, that I might see how the huge strata below, 
which presented so firm and unbroken a frontage, were to be torn up 
and removed. Picks, and wedges, and levers, were applied by my 
brother- workers; and, simple and rude as I had been accustomed to regard 
these implements, I found I had much to learn in the way of using them. 
They all proved inefficient, however, and the workmen had to bore into 
one of the inferior strata, and employ gunpowder. The process was new 
to me, and I deemed it a highly amusing one; it had the merit, too, of 
being attended with some such degree of danger as a boating or rock excur- 
sion, and had thus an interest independent of its novelty. We had a few 
capital shots: the fragments flew in every direction; and an immense 
mass of the diluvium came toppling down, bearing with it two dead birds, 
that in a recent storm had crept into one of the deeper fissures, to die in 
the shelter. I felt a new interest in examining them. The one "was a pretty 
cock goldfinch, with its hood of vermilion, and its wings inlaid with the 
gold to which it owes its name, as unsoiled and smooth as if it had been 
preserved for a museum. The other, a somewhat rarer bird, of the wood- 
pecker tribe, was variegated with light blue and a grayish yellow. I was 
engaged in admiring the poor little things, more disposed to be senti- 
mental, perhaps, than if I had been ten years older, and thinking of the 
contrast between the warmth and jollity of their green summer haunts, 
and the cold and darkness of their last retreat, when I heard our employer 
bidding the workmen lay by their tools. I looked up, and saw the sun 
sinking behind the thick fir wood beside us, and the long dark shadows of 
the trees stretching downwards towards the shore. 

This was no very formidable beginning of the course of life I had so 
much dreaded. To be sure, my hanas were a little sore, and I felt nearly 
as much fatigued as if I had been climbing among the rocks; but I had 
wrought and been useful, and had yet enjoyed the day fully as much as 
usual. It was no small matter, too, that the evening, converted, by a rare 


transmutation, into the delicious "blink of rest" which Burns so truthfully 
describes, was all my own. I was as light of heart next morning as any of 
my brother-workmen. There had been a smart frost during the night, and 
the rime lay white on the grass as we passed onwards through the fields; 
but the sun rose in a clear atmosphere, and the day mellowed, as it 
advanced, into one of those delightful days of early spring which give so 
pleasing an earnest of whatever is mild and genial in the better half of the 

The gunpowder had loosened a large mass in one of the interior strata, 
and our first employment, on resuming our labours, was to raise it from 
its bed. I assisted the other workmen in placing it on edge, and was much 
struck by the appearance of the platform on which it had rested. The 
entire surface was ridged and furrowed like a bank of sand that had been 
left by the tide an hour before. I could trace every bend and curvature, 
every cross hollow and counter ridge, of the corresponding phenomena; 
for the resemblance was no half resemblance, it was the thing itself; 
and I had observed it a hundred and a hundred times, when sailing my 
little schooner in the shallows left by the ebb. But what had become of the 
waves that had thus fretted the solid rock, or of what element had they 
been composed ? I felt as completely at fault as Robinson Crusoe did on his 
discovering the print of the man's foot on the sand. The evening furnished 
me with still further cause of wonder. We raised another block in a 
different part of the quarry, and found that the area of a circular depres- 
sion in the stratum below was broken and flawed in every direction, as 
if it had been the bottom of a pool recently dried up, which had shrunk 
and split in the hardening. Several large stones came rolling down from 
the diluvium in the course of the afternoon. They were of different 
qualities from the sandstone below, and from one another; and, what was 
more wonderful still, they were all rounded and water-worn, as if they had 
been tossed about in the sea or the bed of a river for hundreds of years. 
There could not, surely, be a more conclusive proof that the bank which 
had enclosed them so long could not have been created on the rock on 
which it rested. No workman ever manufactures a half-worn article, and 
the stones were all half -worn! And if not the bank, why then the sand- 
stone underneath? I was lost in conjecture, and found I had food enough 
for thought that evening, without once thinking of the unhappiness of a 
life of labour. 

The immense masses of diluvium which we had to clear away rendered 
the working of the quarry laborious and expensive, and all the party 
quitted it in a few days, to make trial of another that seemed to promise 
better. The one we left is situated, as I have said, on the southern shore 
of an inland bay, the Bay of Cromarty; the one to which we removed 


has been opened in a lofty wall of cliffs that overhangs the northern 
shore of the Moray Frith. I soon found I was to be no loser by the change. 
Not the united labours of a thousand men for more than a thousand years 
could have furnished a better section of the geology of the district than this 
range of cliffs. It may be regarded as a sort of chance dissection on the 
earth's crust. We see in one place the primary rock, with its veins of 
granite and quartz, its dizzy precipices of gneiss, and its huge masses 
o horneblend; we find the secondary rock in another, with its beds of 
sandstone and shale, its spars, its clays, and its nodular limestones. We 
discover the still little-known but highly interesting fossils of the Old 
Red Sandstone in one deposition; we find the beautifully preserved shells 
and lignites of the Lias in another. There are the remains of two several 
creations at once before us. The shore, too, is heaped with rolled fragments 
of almost every variety of rock, basalts, ironstones, hyperstenes, porphy- 
ries, bituminous shales, and micaceous schists. In short, the young geologist, 
had he all Europe before him could hardly choose for himself a better 
field. I had, however, no one to tell me so at the time, for Geology had 
not yet travelled so far north; and so, without guide or vocabulary, I had 
to grope my way as I best might, and find out all its wonders for myself. 
But so slow was the process, and so much was I a seeker in the dark, that 
the facts contained in these few sentences were the patient gatherings of 

In the course of the first day's employment I picked up a nodular mass 
of blue limestone, and laid it open by a stroke of the hammer. Wonder- 
ful to relate, it contained inside a beautifully finished piece of sculpture, 
one of the volutes, apparently, of an Ionic capital; and not the far-famed 
walnut of the fairy tale, had I broken the shell and found the little dog 
lying within, could have surprised me more. Was there another such 
curiosity in the whole world ? I broke open a few other nodules of similar 
appearance, for they lay pretty thickly on the shore, and found that 
there might be. In one of these there were what seemed to be the scales 
of fishes, and the impressions of a few minute bivalves, prettily striated; 
in the centre of another there was actually a piece of decayed wood. Of 
all Nature's riddles, these seemed to me to be at once the most interesting 
and the most difficult to expound. I treasured them carefully up, and was 
told by one of the workmen to whom I showed them, that there was a 
part of the shore about two miles farther to the west where curiously- 
shaped stones, somewhat like the heads of boarding-pikes, were occasion- 
ally picked up; and that in his father's days the country people called 
them thunderbolts, and deemed them of sovereign efficacy in curing 
bewitched cattle. Our employer, on quitting the quarry for the building or* 


which we were to be engaged, gave all the workmen a half-holiday- I 
employed it in visiting the place where the thunderbolts had fallen so 
thickly, and found it a richer scene of wonder than I could have fancied 
in even my dreams. 

What first attracted my notice was a detached group of low-lying 
skerries, wholly different in form and colour from the sandstone cliffs 
above or the primary rocks a little farther to the west. I found them com- 
posed of thin strata of limestone, alternating with thicker beds of a black 
slaty substance, which, as I ascertained in the course of the evening, burns 
with a powerful flame, and emits a strong bituminous odour. The layers 
into which the beds readily separate are hardly an eighth part of an inch 
in thickness, and yet on every layer there are the impressions of thousands 
and tens of thousands of the various fossils peculiar to the Lias. We may 
turn over these wonderful leaves one after one, like the leaves of a 
herbarium, and find the pictorial records of a former creation in every 
page: scallops, and gryphites, and ammonites, of almost every variety 
peculiar to the formation, and at least some eight of ten varieties of 
belemnite; twigs of wood, leaves of plants, cones of an extinct species of 
pine, bits of charcoal, and the scales of fishes; and, as if to render their 
pictorial appearance more striking, though the leaves of this interesting 
volume are of a deep black, most of the impressions are of a chalky white- 
ness. I was lost in admiration and astonishment, and found my very 
imagination paralysed by an assemblage of wonders that seemed to out- 
rival in the fantastic and the extravagant even its wildest conceptions. I 
passed on from ledge to ledge, like the traveller of the tale through the 
city of statues, and at length found one of the supposed aerolites I had 
come in quest of firmly imbedded in a mass of shale. But I had skill 
enough to determine that it was other than what it had been deemed. 
A very near relative, who had been a sailor in his time on almost every 
ocean, and had visited almost every quarter of the globe, had brought 
home one of these meteoric stones with him from the coast of Java. It 
was of a cylindrical shape and vitreous texture, and it seemed to have 
parted in the middle when in a half-molten state, and to have united 
again, somewhat awry, ere it had cooled enough to have lost the adhesive 
quality. But there was nothing organic in its structure; whereas the stone 
I had now found was organized very curiously indeed. It was of a coni- 
cal form and filamentary texture, the filaments radiating in straight lines 
from the centre to the circumference. Finely-marked veins like white 
threads ran transversely through these in its upper half to the point; while 
the space below was occupied by an internal cone, formed of plates that 
lay parallel to the base, and which, like watch-glasses, were concave on the 


under side and convex on the upper. I learned in time to call this stone 
a belemnite, and became acquainted with enough of its history to know 
that it once formed part of a variety of cuttle-fish, long since extinct. 

My first year of labour came to a close, and I found that the amount 
of my happiness had not been less than in the last of my boyhood. My 
knowledge, too, had increased in more than the skill of at least the com- 
mon mechanic, I had fitted myself for independence. The additional 
experience of twenty years has not shown me that there is any necessary 
connection between a life of toil and a life of wretchedness; and when I 
have found good men anticipating a better and a happier time than 
either the present or the past, the conviction that in every period of the 
world's history the great bulk of mankind must pass their days in labour, 
has not in the least inclined me to scepticism. . . . 

One important truth I would fain press on the attention of my low- 
lier readers: there are few professions, however humble, that do not pre- 
sent their peculiar advantages of observation; there are none, I repeat, 
in which the exercise of the faculties does not lead to enjoyment. I 
advise the stone-mason, for instance, to acquaint himself with Geology. 
Much of his time must be spent amid the rocks and quarries of widely- 
separated localities. The bridge or harbour is no sooner completed in one 
district than he has to remove to where the gentleman's seat or farm- 
steading is to be erected in another; and so, in the course of a few years, 
he may pass over the whole geological scale, even when restricted to Scot- 
land, from the Grauwacke of the Lammermuirs, to the Wealden of 
Moray or the Chalk-flints of Banffshire and Aberdeen; and this, too, 
with opportunities of observation at every stage which can be shared with 
him by only the gentleman of fortune who devotes his whole time to the 
study. Nay, in some respects his advantages are superior to those of the 
amateur himself. The latter must often pronounce a formation unfossilif- 
erous when, after the examination of at most a few days, he discovers ir 
it nothing organic; and it will be found that half the mistakes of geolo- 
gists have arisen from conclusions thus hastily formed. But the working 
man, whose employments have to be carried on in the same formation for 
months, perhaps years, together, enjoys better opportunities for arriving 
at just decisions. There are, besides, a thousand varieties of accident which 
lead to discovery, floods, storms, landslips, tides of unusual height, ebbs 
of extraordinary fall; and the man who plies his labour at all seasons in 
the open air has by much the best chance of profiting by these. There 
are formations which yield their organisms slowly to the discoverer, and 
the proofs which establish their place in the geological scale more tardily 
.still. I was acquainted with the Old Red Sandstone of Ross and Cromarty 


for nearly ten years ere I had ascertained that it is richly fossiliferous, 
a discovery which, in exploring this formation in those localities, some of 
our first geologists had failed to anticipate: I was acquainted with it for 
nearly ten years more ere I could assign to its fossils their exact place in 
the scale. 

. . . Should the working man be encouraged by my modicum of success 
to improve his opportunities of observation, I shall have accomplished the 
whole of it. It cannot be too extensively known, that nature is vast and 
knowledge limited, and that no individual, however humble in place 
or acquirement, need despair of adding to the general fund. 


Geological Change 


[James Hutton, 1726-1797] and his school that this globe has not 
always worn the aspect which it bears at present; that on the contrary, 
proofs may everywhere be culled that the land which we now see has 
been formed out of the wreck of an older land. Among these proofs, the 
most obvious are supplied by some of the more' familiar kinds of rocks, 
which teach us that, though they are now portions of the dry land, they 
were originally sheets of gravel, sand, and mud, which had been worn 
from the face of long-vanished continents, and after being spread out 
over the floor of the sea were consolidated into compact stone, and 
were finally broken up and raised once more to form part of the dry 
land. This cycle of change involved two great systems of natural proc- 
esses. On the one hand, men were taught that by the action of running 
water the materials of the solid land are in a state of continual decay and 
transport to the ocean. On the other hand, the ocean floor is liable from 
time to time to be upheaved by some stupendous internal force akin 


to that which gives rise to the volcano and the earthquake. Hutton 
further perceived that not only had the consolidated materials been dis- 
rupted and elevated, but that masses of molten rock had been thrust 
upward among them, and had cooled and crystallized in large bodies 
of granite and other eruptive rocks which form so prominent a feature 
on the earth's surface. 

It was a special characteristic of this philosophical system that it sought 
in the changes now in progress on the earth's surface an explanation of 
those which occurred in older times. Its founder refused to invent causes 
or modes of operation, for those with which he was familiar seemed to 
him adequate to solve the problems with which he attempted to deal. 
Nowhere was the profoundness of his insight more astonishing than in 
the clear, definite way in which he proclaimed and reiterated his doc- 
trine, that every part of the surface of the continents, from mountain 
top to seashore, is continually undergoing decay, and is thus slowly 
travelling to the sea. He saw that no sooner will the sea floor be elevated 
into new land than it must necessarily become a prey to this universal 
and unceasing degradation. He perceived that as the transport of dis- 
integrated material is carried on chiefly by running water, rivers must 
slowly dig out for themselves the channels in which they flow, and thus 
that a system of valleys, radiating from the water parting of a country, 
must necessarily result from the descent of the streams from the moun- 
tain crests to the sea. He discerned that this ceaseless and wide-spread 
decay would eventually lead to the entire demolition of the dry land, but 
he contended that from time to time this catastrophe is prevented by the 
operation of the under-ground forces, whereby new continents are up- 
heaved from the bed of the ocean. And thus in his system a due 
proportion is maintained between land and water, and the condition of 
the earth as a habitable globe is preserved. 

A theory of the earth so simple in outline, so bold in conception, so 
full of suggestion, and resting on so broad a base of observation and 
reflection, ought (we think) to have commanded at once the attention 
of men of science, even if it did not immediately awaken the interest 
of the outside world; but, as Playfair sorrowfully admitted, it attracted 
notice only very slowly, and several years elapsed before any one showed 
himself publicly concerned about it, either as an enemy or a friend. 
Some of its earliest critics assailed it for what they asserted to be its 
irreligious tendency, an accusation which Hutton repudiated with much 
warmth. The sneer levelled by Cowper a few years earlier at all inquiries 
into the history of the universe was perfectly natural and intelligible from 
that poer's point of view. There was then a wide-spread belief that this 


world came into existence some six thousand years ago, and that any 
attempt greatly to increase that antiquity was meant as a blow to the 
authority of Holy Writ. So far, however, from aiming at the overthrow 
o orthodox beliefs, Hutton evidently regarded his "Theory" as an 
important contribution in aid of natural religion. He dwelt with 
unfeigned pleasure on the multitude of proofs which he was able to 
accumulate of an orderly design in the operations of Nature, decay and 
renovation being so nicely balanced as to maintain the habitable con- 
dition of the planet. But as he refused to admit the predominance of 
violent action in terrestrial changes, and on the contrary contended for 
the efficacy of the quiet, continuous processes which we can even now 
see at work around us, he was constrained to require an unlimited 
duration of past time for the production of those revolutions of which 
he perceived such clear and abundant proofs in the crust of the earth. 
The general public, however, failed to comprehend that the doctrine of 
the high antiquity of the globe was not inconsistent with the com- 
paratively recent appearance of man, a distinction which seems so 
obvious now. 

Hutton died in 1797, beloved and regretted by the circle of friends 
who had learned to appreciate his estimable character and to admire his 
genius, but with little recognition from the world at large. Men knew 
not then that a great master had passed away from their midst, who 
had laid broad and deep the foundations of a new science; that his name 
would become a household word in after generations, and that pilgrims 
would come from distant lands to visit the scenes from which he drew 
his inspiration. . . . 

Clear as was the insight and sagacious the inferences of the great 
masters [of the Edinburgh school] in regard to the history of the globe, 
their vision was necessarily limited by the comparatively narrow range 
of ascertained fact which up to their time had been established. They 
taught men to recognize that the present world is built of the ruins of 
an earlier one, and they explained with admirable perspicacity the oper- 
ation of the processes whereby the degradation and renovation of land 
are brought about. But they never dreamed that a long and orderly series 
of such successive destructions and renewals had taken place and had 
left their records in the crust of the earth. They never imagined that 
from these records it would be possible to establish a determinate 
chronology that could be read everywhere and applied to the elucidation 
of the remotest quarter of the globe. It was by the memorable observa- 
tions and generalizations of William Smith that this vast extension of 
our knowledge of the past history of the earth became possible. While 


the Scottish philosophers were building up their theory here, Smith was 
quietly ascertaining by extended journeys that the stratified rocks of the 
west of England occur in a definite sequence, and that each well-marked 
group of them can be discriminated from the others and identified across 
the country by means of its inclosed organic remains. It is nearly a hun- 
dred years since he made known his views, so that by a curious coin- 
cidence we may fitly celebrate on this occasion the centenary of William 
Smith as well as that of James Hutton. No single discovery has ever had 
a more momentous and far-reaching influence on the progress of a 
science than that law of organic succession which Smith established. At 
first it served merely to determine the order of the stratified rocks of 
England. But it soon proved to possess a world-wide value, for it was 
found to furnish the key to the structure of the whole stratified crust 
of the earth. It showed that within that crust lie the chronicles of a long 
history of plant and animal life upon this planet, it supplied the means 
of arranging the materials for this history in true chronological sequence, 
and it thus opened out a magnificent vista through a vast series of ages, 
each marked by its own distinctive types of organic life, which, in pro- 
portion to their antiquity, departed more and more from the aspect of the 
living world. 

Thus a hundred years ago, by the brilliant theory of Hutton and the 
fruitful generalization of Smith, the study of the earth received in our 
country the impetus which has given birth to the modern science of 
geology. . . . 

From the earliest times the natural features of the earth's surface have 
arrested the attention of mankind. The rugged mountain, the cleft ravine, 
the scarped cliff, the solitary bowlder, have stimulated curiosity and 
prompted many a speculation as to their origin. The shells embedded by 
millions in the solid rocks of hills far removed from the seas have still 
further pressed home these "obstinate questionings." But for many long 
centuries the advance of inquiry into such matters was arrested by the 
paramount influence of orthodox theology. It was not merely that the 
church opposed itself to the simple and obvious interpretation of these 
natural phenomena. So implicit had faith become in the accepted views 
of the earth's age and of the history of creation, that even laymen of 
intelligence and learning set themselves unbidden and in perfect good 
faith to explain away the difficulties which nature so persistently raised 
up, and to reconcile her teachings with those of the theologians. . . . 

It is the special glory of the Edinburgh school of geology to have cast 
aside all this fanciful trifling. Hutton boldly proclaimed that it was no 
part of his philosophy to account for the beginning of things. His con- 


cern lay only with the evidence furnished by the earth itself as to its 
origin. With the intuition of true genius he early perceived that the only 
basis from which to explore what has taken place in bygone time is a 
knowledge of what is taking place to-day. He thus founded his system 
upon a careful study of the process whereby geological changes are now 
brought about. . . . 

Fresh life was now breathed into the study of the earth. A new spirit 
seemed to animate the advance along every pathway of inquiry. Facts 
that had long been familiar came to possess a wider and deeper meaning 
when their connection with each other was recognized as parts of one 
great harmonious system of continuous change. In no department of 
Nature, for example, was this broader vision more remarkably displayed 
than in that wherein the circulation of water between land and sea plays 
the most conspicuous part. From the earliest times men had watched the 
coming of clouds, the fall of rain, the flow of rivers, and had recognized 
that on this nicely adjusted machinery the beauty and fertility of the land 
depend. But they now learned that this beauty and fertility involve a 
continual decay of the terrestrial surface; that the soil is a measure of this 
decay, and would cease to afford us maintenance were it not continually 
removed and renewed, that through the ceaseless transport of soil by 
rivers to the sea the face of the land is slowly lowered in level and carved 
into mountain and valley, and that the materials thus borne outwards to 
the floor of the ocean are not lost, but accumulate there to form rocks, 
which in the end will be upraised into new lands. Decay and renovation, 
in well-balanced proportions, were thus shown to be the system on which 
the existence of the earth as a habitable globe had been established. It 
was impossible to conceive that the economy of the planet could be main- 
tained on any other basis. Without the circulation of water the life of 
plants and animals would be impossible, and with the circulation the 
decay of the surface of the; land and the renovation of its disintegrated 
materials are necessarily involved. 

As it is now, so must it have been in past time. Hutton and Playfair 
pointed to the stratified rocks of the earth's crust as demonstrations that 
the same processes which are at work to-day have been in operation from 
a remote antiquity. . . . 

Obviously, however, human experience, in the few centuries during 
which attention has been turned to such subjects, has been too brief to 
warrant any dogmatic assumption that the various natural processes 
must have been carried on in the past with the same energy and at the 
same rate as they are carried on now. ... It was an error to take for 
granted that no other kind of process or influence, nor any variation in 


the rate of activity save those of which man has had actual cognizance, 
has played a part in the terrestrial economy. The uniformitarian writers 
laid themselves open to the charge of maintaining a kind of perpetual 
motion in the machinery of Nature. They could find in the records of the 
earth's history no evidence of a beginning, no prospect of an end. . . . 

The discoveries of William Smith, had they been adequately under- 
stood, would have been seen to offer a corrective to this rigidly uni- 
formitarian conception, for they revealed that the crust of the earth con- 
tains the long record of an unmistakable order of progression in organic 
types. They proved that plants and animals have varied widely in suc- 
cessive periods of the earth's history; the present condition of organic 
life being only the latest phase of a long preceding series, each stage of 
which recedes further from the existing aspect of things as we trace it 
backward into the past. And though no relic had yet been found, or 
indeed was ever likely to be found, of the first living things that appeared 
upon the earth's surface, the manifest simplification of types in the 
older formations pointed irresistibly to some beginning from which the 
long procession has taken its start. If then it could thus be demonstrated 
that there had been upon the globe an orderly march of living forms 
from the lowliest grades in early times to man himself to-day, and thus 
that in one department of her domain, extending through the greater 
portion of the records of the earth's history, Nature had not been 
uniform, but had followed a vast and noble plan of evolution, surely it 
might have been expected that those who discovered and made known 
this plan would seek to ascertain whether some analogous physical pro- 
gression from a definite beginning might not be discernible in the frame- 
work of the globe itself. 

But the early masters of the science labored under two great disad- 
vantages. In the first place, they found the oldest records of the earth's 
history so broken up and effaced as to be no longer legible. And in the 
second place, . . . they considered themselves bound to search for facts, 
not to build up theories; and as in the crust of the earth they could find 
no facts which threw any light upon the primeval constitution and sub- 
sequent development of our planet, they shut their ears to any theoretical 
interpretations that might be offered from other departments of science. . . . 

What the more extreme members of the uniformitarian school failed 
to perceive was the absence of all evidence that terrestrial catastrophes 
even on a colossal scale might not be a part of the present economy of 
this globe. Such occurrences might never seriously affect the whole 
earth at one time, and might return at such wide intervals that no 
example of them has yet been chronicled by man. But that they have 


occurred again and again, and even within comparatively recent geolog- 
ical times, hardly admits of serious doubt. . . . 

As the most recent and best known of these great transformations, the 
Ice Age stands out conspicuously before us. ... There can not be any 
doubt that after man had become a denizen of the earth, a great physical 
change came over the Northern hemisphere. The climate, which had 
previously been so mild that evergreen trees flourished within ten or 
twelve degrees of the North Pole, now became so severe that vast sheets 
of snow and ice covered the north of Europe and crept southward beyond 
the south coast of Ireland, almost as far as the southern shores of 
England, and across the Baltic into France and Germany. This Arctic 
transformation was not an episode that lasted merely a few seasons, and 
left the land to resume thereafter its ancient aspect. With various suc- 
cessive fluctuations it must have endured for many thousands of years. 
When it began to disappear it probably faded away as slowly and 
imperceptibly as it had advanced, and when it finally vanished it left 
Europe and North America profoundly changed in the character alike 
of their scenery and of their inhabitants. The rugged rocky contours of 
earlier times were ground smooth and polished by the march of the ice 
across them, while the lower grounds were buried under wide and thick 
sheets of clay, gravel, and sand, left behind by the melting ice. The 
varied and abundant flora which had spread so far within the Arctic 
circle was driven away into more southern and less ungenial climes. 
But most memorable of all was the extirpation of the prominent large 
animals which, before the advent of the ice, had roamed over Europe. 
The lions, hyenas, wild horses, hippopotamuses, and other creatures 
either became entirely extinct or were driven into the Mediterranean 
basin and into Africa. In their place came northern forms the reindeer, 
glutton, musk ox, wooly rhinoceros, and mammoth. 

Such a marvellous transformation in climate, in scenery, in vegetation 
and in inhabitants, within what was after all but a brief portion of 
geological time, though it may have involved no sudden or violent con- 
vulsion, is surely entitled to rank as a catastrophe in the history of the 
globe. It was probably brought about mainly if not entirely by the oper- 
ation of forces external to the earth. No similar calamity having befallen 
the continents within the time during which man has been recording his 
experience, the Ice Age might be cited as a contradiction to the doc- 
trine of uniformity. And yet it manifestly arrived as part of the estab- 
lished order of Nature. Whether or not we grant that other ice ages 
preceded the last great one, we must admit that the conditions under 
which it arose, so far as we know them, might conceivably have occurred 


before and may occur again. The various agencies called into play by the 
extensive refrigeration of the Northern hemisphere were not different from 
those with which we are familiar. Snow fell and glaciers crept as they 
do to-day. Ice scored and polished rocks exactly as it still does among 
the Alps and in Norway. There was nothing abnormal in the phenomena, 
save the scale on which they were manifested. And thus, taking a broad 
view of the whole subject, we recognize the catastrophe, while at the 
same time we see in its progress the operation of those same natural 
processes which we know to be integral parts of the machinery whereby 
the surface of the earth is continually transformed. 

Among the debts which science owes to the Huttonian school, not the 
least memorable is the promulgation of the first well-founded con- 
ceptions of the high antiquity of the globe. Some six thousand years had 
previously been believed to comprise the whole life of the planet, and 
indeed of the entire universe. When the curtain was then first raised 
that had veiled the history of the earth, and men, looking beyond the 
brief span within which they had supposed that history to have been 
transacted, beheld the records of a long vista of ages stretching far away 
into a dim illimitable past, the prospect vividly impressed their imagina- 
tion. Astronomy had made known the immeasurable fields of space; the 
new science of geology seemed now to reveal boundless distances of 
time. . . . 

The universal degradation of the land, so notable a characteristic of 
the earth's surface, has been regarded as an extremely slow process. 
Though it goes on without ceasing, yet from century to century it seems 
to leave hardly any perceptible trace on the landscapes of a country. 
Mountains and plains, hills and valleys appear to wear the same familiar 
aspect which is indicated in the oldest pages of history. This obvious 
slowness in one of the most important departments of geological activity 
doubtless contributed in large measure to form and foster a vague belief 
in the vastness of the antiquity required for the evolution of the earth. 

But, as geologists eventually came to perceive, the rate of degradation 
of the land is capable of actual measurement. The amount of material 
worn away from the surface of any drainage basin and carried in the 
form of mud, sand, or gravel, by the main river into the sea represents 
the extent to which that surface has been lowered by waste in any given 
period of time. But denudation and deposition must be equivalent to 
each other. As much material must be laid down in sedimentary accumu- 
lations as has been mechanically removed, so that in measuring the 
annual bulk of sediment borne into the sea by a river, we obtain a clue 


not only to the rate of denudation of the land, but also to the rate at 
which the deposition of new sedimentary formations takes place. . . . 

But in actual fact the testimony in favor of the slow accumulation and 
high antiquity of the geological record is much stronger than might be 
inferred from the mere thickness of the stratified formations. These 
sedimentary deposits have not been laid down in one unbroken sequence, 
but have had their continuity interrupted again and again by upheaval 
and depression. So fragmentary are they in some regions that we can 
easily demonstrate the length of time represented there by still existing 
sedimentary strata to be vastly less than the time indicated by the gaps in 
the series. 

There is yet a further and impressive body of evidence furnished by 
the successive races of plants and animals which have lived upon the 
earth and have left their remains sealed up within its rocky crust. No 
universal destructions of organic life are chronicled in the stratified rocks. 
It is everywhere admitted that, from the remotest times up to the pres- 
ent day, there has been an onward march of development, type succeed- 
ing type in one long continuous progression. As to the rate of this evolu- 
tion precise data are wanting. There is, however, the important negative 
argument furnished by the absence of evidence of recognizable specific 
variations of organic forms since man began to observe and record. We 
know that within human experience a few species have become extinct, 
but there is no conclusive proof that a single new species have come into 
existence, nor are appreciable variations readily apparent in forms that 
live in a wild state. The seeds and plants found with Egyptian mummies, 
and the flowers and fruits depicted on Egyptian tombs, are easily identi- 
fied with the vegetation of modern Egypt. The embalmed bodies of 
animals found in that country show no sensible divergence from the 
structure or proportions of the same animals at the present day. The 
human races of Northern Africa and Western Asia were already as 
distinct when portrayed by the ancient Egyptian artists as they are now, 
and they do not seem to have undergone any perceptible change since 
then. Thus a lapse of four or five thousand years has not been accom- 
panied by any recognizable variation in such forms of plant and animal 
life as can be tendered in evidence. Absence of sensible change in these 
instances is, of course, no proof that considerable alteration may not have 
been accomplished in other forms more exposed to vicissitudes of 
climate and other external influences. But it furnishes at least a presump- 
tion in favor of the extremely tardy progress of organic variation. 

If, however, we extend our vision beyond the narrow range of human 
history, and look at the remains of the plants and animals preserved in 


those younger formations which, though recent when regarded as parts 
of the whole geological record, must be many thousands of years older 
than the very oldest of human monuments, we encounter the most 
impressive proofs of the persistence of specific forms. Shells which lived 
in our seas before the coming of the Ice Age present the very same 
peculiarities of form, structure, and ornament which their descendants 
still possess. The lapse of so enormous an interval of time has not 
sufficed seriously to modify them. So too with the plants and the higher 
animals which still survive. Some forms have become extinct, but few 
or none which remain display any transitional gradations into new 
species. We must admit that such transitions have occurred, that indeed 
they have been in progress ever since organized existence began upon 
our planet, and are doubtless taking place now. But we can not detect 
them on the way, and we feel constrained to believe that their march 
must be excessively slow. . . . 

If the many thousands of years which have elapsed since the Ice Age 
have produced no appreciable modification of surviving plants and 
animals, how vast a period must have been required for that marvellous 
scheme of organic development which is chronicled in the rocks! . . . 

I have reserved for final consideration a branch of the history of the 
earth which, while it has become, within the lifetime of the present 
generation, one of the most interesting and fascinating departments of 
geological inquiry, owed its first impulse to the far-seeing intellects of 
Hutton and Playfair. With the penetration of genius these illustrious 
teachers perceived that if the broad masses of land and the great chains 
of mountains owe their origin to stupendous movements which from 
time to time have convulsed the earth, their details of contour must be 
mainly due to the eroding power of running water. They recognized 
that as the surface of the land is continually worn down, it is essentially 
by a process of sculpture that the physiognomy of every country has been 
developed, valleys being hollowed out and hills left standing, and that 
these inequalities in topographical detail are only varying and local 
accidents in the progress of the one great process of the degradation of 
the land. 

From the broad and guiding outlines of theory thus sketched we 
have now advanced amid ever-widening multiplicity of detail into a 
fuller and nobler conception of the origin of scenery. The law of evolu- 
tion is written as legibly on the landscapes of the earth as on any other 
page of the book of Nature. Not only do we recognize that the existing 
topography of the continents, instead of being primeval in origin, has 
gradually been developed after many precedent mutations, but we are 


enabled to trace these earlier revolutions in the structure of every hill 
and glen. Each mountain chain is thus found to be a memorial of many 
successive stages in geographical evolution. Within certain limits land and 
sea have changed places again and again. Volcanoes have broken out 
and have become extinct in many countries long before the advent of 
man. Whole tribes of plants and animals have meanwhile come and 
gone, and in leaving their remains behind them as monuments at once 
of the slow development of organic types, and of the prolonged vicissi- 
tudes of the terrestrial surface, have furnished materials for a chrono- 
logical arrangement of the earth's topographical features. Nor is it only 
from the organisms of former epochs that broad generalizations may be 
drawn regarding revolutions in geography. The living plants and animals 
of to-day have been discovered to be eloquent of ancient geographical 
features that have long since vanished. In their distribution they tell us 
that climates have changed; that islands have been disjoined from con- 
tinents; that oceans once united have been divided from each other, or 
once separate have now been joined; that some tracts of land have 
disappeared, while others for prolonged periods of time have remained 
in isolation. The present and the past are thus linked together, not 
merely by dead matter, but by the world of living things, into one vast 
system of continuous progression. 


Earthquakes What Are They? 


certain belts in which earthquakes occur more often than in other 
parts of the world. Why should this be the case? We read from time to 
time of destructive earthquakes in Japan. But many lesser shocks occur there 
of which we never hear. In fact, there is an earthquake, large or small, 
somewhere in Japan practically every day. Similarly, the Kurile Islands, 
the Aleutian Islands, Alaska and the Queen Charlotte Islands are subject 
to frequent earth shocks. Continuing around the Pacific circle, we meet 
with many earthquakes in California, Mexico, Central America, Vene- 
zuela, Colombia, Ecuador, Bolivia, Peru and Chili. And on the other 
side of the Pacific Ocean, the earthquake belt continues from Japan 
southward through Formosa and the Philippine Deep to New Zealand. 
Another somewhat less striking earthquake zone runs from Mexico and 
the Antilles through the northern Mediterranean countries and Asia 
Minor into the Pamirs, Turkestan, Assam and the Indian Ocean. In other 
parts of the earth, destructive earthquakes also occur, but as more or less 
isolated phenomena. Examples in this country are the Mississippi Valley 
earthquakes of 1811 and of the following year, and the Charleston earth- 
quake of 1886. 

Now why should destructive earthquakes occur more frequently in 
such a zone or belt as the border of the Pacific Ocean? What is an 
earthquake? Centuries ago, many people, and even scientific men, 
thought that earthquakes were caused by explosions down in the earth; 
and there have not been wanting men in our own time who held this 
view. Others, like Alexander von Humboldt, thought that earthquakes 
were connected with volcanoes; that the earth is a ball of molten lava 
covered by a thin shell of rock and that the volcanoes were a sort of 
safety valve. As long as the volcanoes are active, they said, the pressure 
within the molten lava of the earth is held down, but when the volcanoes 



cease their activity, thus closing the safety valves, so to speak, the increas- 
ing pressure eventually causes a fracture in the earth's crust. Another 
theory supposed that the lava occupied passageways in a more or less 
solid portion of the earth underneath the crust and that the movement of 
lava within these passages caused such pressure as to burst their walls, 
thus causing an earthquake. 

Quite a different point of view was taken by those who held the theory 
that earthquakes occurred within the uppermost crust of the earth. This 
crust was supposed to be honeycombed with vast caves. Even the whole 
mountain chain of the Alps was thought to be an immense arch built 
up over a cavern. When the arch should break, thus allowing the overly- 
ing rocks to drop somewhat, we would have an earthquake. In many 
cases, those who held this theory believed that the entire roof would 
collapse and that earthquakes are generally due to the impact of the 
falling mass of rocks on the floor of the cavern. 

But it has been shown, since the discovery of the passage of earthquake 
waves through the earth and their registration by means of seismographs, 
that the outer portion of the earth down to a depth of at least five 
elevenths of the earth's radius is not only solid, but, with the exception of 
the outer layers, is more than twice as rigid as steel in the laboratory. 
It has also been shown that volcanoes are a purely surface phenomenon; 
that they have no connection with each other, even when they are but 
a few miles apart. Hence it is clear that earthquakes connected with 
volcanoes must be of very local character, if they are to be caused by the 
movement of lava. This is found to be actually the case. It is also clear 
that some other cause must operate in producing earthquakes, since 
destructive earthquakes often occur very far from volcanoes. In fact, 
some regions where there are frequent earthquakes have no volcanoes 
at all. 

In the California earthquake of 1906, there occurred a fracture of the 
earth's crust which could be followed at the surface for a distance of 
more than 150 miles, extending from the Gualala River Valley on the 
northern coast of California southeastward through Tomales Bay and 
outside the Golden Gate to the old mission of San Juan Bautista. The 
rocks on the east side of this fracture moved southeastward relatively to 
those on the west side, so that every road, fence or other structure which 
had been built across the line of fracture was offset by varying amounts 
up to twenty-one feet. A study of this earthquake led scientific men to the 
conclusion that the mechanism of the earthquake was an elastic rebound. 
It was thought that the rocks in the portion of the earth's crust west of 
the fracture had been draped northward until the ultimate strength of 


the rocks was reached along this zone of weakness. When the fracture 
occurred, the rocks, like bent springs, sprang back to an unstrained 
position. But this did not occur in one continuous throw, but in a series 
of jerks, each of which set up elastic vibrations in the rocks. These 
vibrations traveled out in all directions and constituted the earthquake 
proper. The zone of weakness in which the California earthquake 
occurred is a valley known as the San Andreas rift. It is usually quite 
straight and ignores entirely the physiography of the region, passing 
indifferently over lowlands and mountains and extending more than 300 
miles beyond the end of the fracture of 1906 until it is lost in the Colorado 
desert east of San Bernardino. The entire floor of the valley has been 
broken up by earthquakes occurring through the ages into small blocks 
and ridges and even into rock flour. 

The San Andreas rift is only one of the many features which parallel 
the Pacific Coast in California. There are other lesser rifts on which 
earthquakes have occurred. Similar to these rifts in some respects are 
the ocean deeps, along the walls of which occur some of the world's 
most violent earthquakes. 

Why do these features parallel the Pacific shore? And why are earth- 
quakes associated with them? Both seem to be connected in some way 
with the process of mountain-building, for many of the features in this 
circum-Pacific belt are geologically recent. Many have thought that 
mountain-building in general and the processes going on around the 
Pacific in particular are due to a shortening of the earth's crust caused by 
gradual cooling of the interior and the consequent shrinkage, but this 
is not evident. While the earth is surely losing heat by radiation into 
space, it is being heated by physical and chemical processes connected 
with radioactivity at such a rate that, unless the radioactive minerals are 
confined to the uppermost ten miles or so of the earth's crust, the earth 
must be getting hotter instead of cooler, because the amount of heat 
generated must exceed that which is conducted to the surface and radiated 

Another suggested cause of earthquakes is isostatic compensation. If 
we take a column of rock extending downward from the top of a moun- 
tain chain to a given level within the earth's crust and compare it with 
another column extending to the same level under a plain, the mountain 
column will be considerably longer than the other and consequently will 
contain more rock. Hence it should weigh more, unless the rocks of which 
it is composed are lighter than those under the plain, but geodesists tell 
us that the two columns weigh the same. Hence the rocks under the 
plain must be the heavier of the two. But even if this is the case, we 


should expect the conditions to change; for rain and weather are continu- 
ally removing rocks from the tops of the mountains and distributing the 
materials of which they are composed over the plain. Nevertheless, 
according to the geodesists, the columns continue to weigh the same. 
Hence we must conclude that compensation in some form must be taking 
place. There must be an inflow of rock into the mountain column and 
an outflow from the plain column. But the cold flow of a portion of a 
mass of rock must place enormous strain on the surrounding portions. 
When the stress reaches the ultimate strength of the rocks, there must be 
fracture and a relief of strain, thus causing an earthquake. 

It has recently been found that earthquakes occur at considerable depth 
in the earth. Hence they can not be caused by purely surface strains. 
There are a few earthquakes which seem to have occurred at depths 
up to 300 miles. This is far below the depth of compensation of the 
geodesists. It is also below the zone of fracture of the geologists, and far 
down in what they call the zone of flow. Can an earthquake be generated 
by a simple regional flow? We do not know, but it would seem that 
sudden release of strain is necessary to cause the vibrations which we 
call an earthquake. It may be that a strain is produced and gradually 
grows in such a way as to produce planes of shear such as occur when 
a column is compressed lengthwise. These planes of maximum shear 
usually form an angle of about forty-five degrees with the direction of 
the force. Recent investigation into the failure of steel indicates that under 
certain conditions it will retain its full strength up to the moment of 
failure when the steel becomes as plastic as mud along the planes of 
maximum shear. The two portions of the column then glide over each 
other on the plastic zone until the strain is relieved, whereupon the steel 
within the zone becomes hard and rigid as before. It may be that a 
process somewhat similar to this may take place deep down in the earth, 
and that the sheared surface may be propagated upwards through the 
zone of flow to the zone of fracture and even to the surface of the earth. 
In that case, the plastic shear would give way to true fracture near the 

It is only by a careful study, not only of the waves produced by earth- 
quakes and of the permanent displacements which occur in them, but of 
the actual movement along the planes of fracture, that we shall be able 
to discover what an earthquake really is. For the present, we must be 
satisfied with knowing that it is an elastic process; that it is usually 
destructive only within a very restricted belt, and that it is probably 
produced by the sudden release of a regional strain within the crust of 
the earth. 

Last Days of St. Pierre 


From Disaster Fighters 



JL JL Clerc. Little past the age of forty, in this year of 1902, he was the 
leading planter of the fair island of Martinique. Sugar from his broad 
cane fields, molasses, and mellow rum had made him a man of wealth, 
a millionaire. All his enterprises prospered. 

Were the West Indies, for all their beauty and their bounty, sometimes 
powerless to prevent a sense of exile, an ache of homesickness in the 
heart of a citizen of the Republic? Then there again fate had been kind 
to Fernand Clerc. Elected a member of the Chamber of Deputies, it was 
periodically his duty and his pleasure to embark and sail home to attend 
its sessions home to France, to Paris. 

Able, respected, good-looking, blessed with a charming wife and 
children, M. Clerc found life good indeed. With energy undepleted by 
the tropics, he rode through the island visiting his properties. Tall and 
thick grew the cane stalks of his plantation at Vive on the slopes of 
Mont Pelee. Mont Pelee Naked Mountain well named when lava 
erupting from its cone had stripped it bare of its verdure. But that was 
long ago. Not since 1851 had its subterranean fires flared up and then 
but insignificantly. Peaceful now, its crater held the lovely Lake of 
Palms, whose wooded shores were a favorite picnic spot for parties from 
St. Pierre and Fort-de-France. Who need fear towering Mont Pelee, once 
mighty, now mild, an extinct volcano? 

Yet this spring M. Clerc and all Martinique received a rude shock. 
The mountain was not dead, it seemed. White vapors veiled her sum- 
mit, and by May 2nd she had overlaid her green mantle with a gown 



of gray cinders. Pelee muttered and fumed like an angry woman told 
her day was long past. Black smoke poured forth, illumined at night by 
jets of flame and flashes of lightning. The grayish snow of cinders covered 
the countryside, and the milky waters of the Riviere Blanche altered into 
a muddy and menacing torrent. 

Nor was Pelee uttering only empty threats. On May 5th, M. Clerc at 
Vive beheld a cloud rolling from the mountain down the valley. Sparing 
his own acres, the cloud and the stream of smoking lava which it masked, 
enveloped the Guerin sugar factory, burying its owner, his wife, over- 
seer, and twenty-five workmen and domestics. 

Dismayed by this tragedy, M. Clerc and many others moved from the 
slopes into St. Pierre. The city was crowded, its population of 25,000 
swollen to 40,000, and the throngs that filled the market and the cafes 
or strolled through the gorgeously luxuriant Jardin des Plantes lent an 
air of added animation, of almost hectic gaiety. When M. Clerc professed 
alarm at the behavior of Pelee to his friends, he was answered with 
shrugs of shoulders. Danger? On the slopes perhaps, but scarcely here in 
St. Pierre down by the sea. 

Thunderous, scintillant, Mont Pelee staged a magnificent display of 
natural fireworks on the night of May 7th. Whites and negroes stared up 
at it, fascinated. Some were frightened but more took a child-like joy 
in the vivid spectacle. It was as if the old volcano were celebrating the 
advent of tomorrow's fete day. 

M. Fernand Clerc did not sleep well that night. He breakfasted early 
in the household where he and his family were guests and again expressed 
his apprehensions to the large group of friends and relatives gathered 
at the table. Politely and deferentially for one does not jeer a personage 
and man of proven courage they heard him out, hiding their scepticism. 

The voice of the planter halted in mid-sentence; and he half rose, his 
eyes fixed on the barometer. Its needle was actually fluttering! 

M. Clerc pushed back his chair abruptly and commanded his carriage 
at once. A meaning look to his wife and four children, and they hastened 
to make ready. Their hosts and the rest followed them to the door. Non f 
merely none would join their exodus. Au revoir. A demain. 

From the balcony of their home, the American Consul, Thomas 
Prentis, and his wife waved to the Clerc family driving by. "Stop," the 
planter ordered and the carriage pulled up. Best come along, the planter 
urged. His American friends thanked him. There was no danger, they 
laughed, and waved again to the carriage disappearing in gray dust as 
racing hoofs and wheels sped it out of the city of St. Pierre. 



Governor Mouttet, ruling Martinique for the Republic of France, 
glared up at rebellious Mont Pelee. This peste of a volcano was deranging 
the island. There had been no such crisis since its captures by the English, 
who always relinquished it again to France, or the days when the slaves 
revolted. A great pity that circumstances beyond his control should dam- 
age the prosperous record of his administration, the Governor reflected. 

That miserable mountain was disrupting commerce. Its rumblings 
drowned out the band concerts in the Savane. Its pyrotechnics distracted 
glances which might far better have dwelt admiringly on the proverbial 
beauty of the women of Martinique. . . . Now attention was diverted to a 
cruder work of Nature, a sputtering volcano. Parbleul It was enough 
to scandalize any true Frenchman. 

Governor Mouttet sighed and pored over the reports laid before him. 
He had appointed a commission to study the eruption and get at the 
bottom of I'affaire Pelee, but meanwhile alarm was spreading. People 
were fleeing the countryside and thronging into St. Pierre, deserting that 
city for Fort-de-France, planning even to leave the island. Steamship 
passage was in heavy demand. The Roraima, due May 8th, was booked 
solid out of St. Pierre, one said. This would never do. Steps must be 
taken to prevent a panic which would scatter fugitives throughout Mar- 
tinique or drain a colony of France of its inhabitants. 

A detachment of troops was despatched by the Governor to St. Pierre 
to preserve order and halt the exodus. His Excellency, no man to send 
others where he himself would not venture, followed with Mme. Mouttet 
and took up residence in that city. Certainly his presence must serve to 
calm these unreasoning, exaggerated fears. He circulated among the 
populace, speaking soothing words. Mes enfants, the Governor avowed, 
Mont Pelee rumbling away there is only snoring soundly in deep slum- 
ber. Be tranquil. 

Yet, on the ominous night of May 7th, as spurts of flame painted the 
heavens, the Governor privately confessed to inward qualms. What if 
the mountain should really rouse? Might it not then cast the mortals at 
its feet into a sleep deeper than its own had been, a sleep from which 
they would never awaken? 


Ellery S. Scott, chief officer of the Quebec Line steamship Roraima, 
stood on the bridge with Captain Muggah as the vessel bore down on 
Martinique. A column of smoke over the horizon traced down to the 


4,500-foot summit of Mont Pelee. So the old volcano was acting up! 
Curiosity on the bridge ran high as anchor was dropped in the St. Pierre 
roadstead about 6 o'clock on the morning of May 8th. But all seemed well 
ashore. The streets, twisting and climbing between the bright-colored 
houses, were filled with crowds in gay holiday attire. 

Promptly the agents came aboard. The volcano? But certainly it was 
erupting and causing inconvenience. But there was no danger, regardless 
of the opinion of that Italian skipper yesterday who had said that had 
he seen Vesuvius looking like Pelee, he would have departed from 
Naples as fast as he was going to leave St. Pierre. Although the authorities 
refused him clearance and threatened penalties, he had sailed in haste, 
with only half his cargo. 

By the way, the agents continued, the passenger list was to be consid- 
erably augmented: sixty first-class anxious to leave St. Pierre. Here they 
were boarding now with bag and baggage. Could they be humored, and 
the Roraima sail for St. Lucia at once, returning to discharge its Mar- 
tinique cargo? the agents inquired of Captain Muggah. 

Chief Officer Scott, ordered below to inspect the stowage, thought of 
his boy in the forecastle. A good lad this eldest son of his. Used to say 
he'd have a ship of his own some day and keep on his father as first mate. 
No, his father planned a better career than the sea for him. The boy was 
slated to go to college and be a lawyer. This would be his last voyage. 

Stowed shipshape and proper as Scott knew he would find it, the 
cargo plainly could not be shifted without a good deal of difficulty. The 
Martinique consignment lay above that for St. Lucia, and it would be 
a heavy task to discharge at the latter port first. Scott so reported. 

The agents hesitated briefly. To be sure, sixty first-class passengers were 
to be obliged if possible but ah, well, let them wait a little longer. The 
Roraima would sail as soon as the upper layer of cargo was landed. 

Ship's bells tolled the passing hours. Pelee yonder growled hoarsely and 
belched black smoke. A little before 8, Chief Officer Scott apprehensively 
turned his binoculars on the summit. 


It was dark in the underground dungeon of the St. Pierre prison, but 
thin rays of light filtered through the grated opening in the upper part 
of the cell door. Enough so that Auguste Ciparis could tell when it was 
night and when it was day. 

Not that it mattered much unless a man desired to count the days 
until he should be free. What good was that ? One could not hurry them 
by. Therefore Auguste stolidly endured them with the long patience 


of Africa. The judge had declared him a criminal and caused him to 
be locked up here. Thus it was settled and nothing was to be done. Yet 
it was hard, this being shut out of life up there in the gay city hard 
when one was only twenty-five and strong and lusty. 

Auguste slept and dozed all he could. Pelee was rumbling away in the 
distance each day the jailer bringing him food and water seemed more 
excited about it but the noise, reaching the subterranean cell only as 
faint thunder, failed to keep the negro awake. . . . 

Glimmerings of the dawn of May 8th filtered through the grating into 
the cell, and Auguste stirred into wakefulness. This being a fete day, 
imprisonment was less tolerable. What merriment his friends would be 
making up there in the squares of St. Pierre! He could imagine the side- 
long glances and the swaying hips of the mulatto girls he might have 
been meeting today. Auguste stared sullenly at the cell door. At least the 
jailer might have been on time with his breakfast. 

The patch of light in the grating winked out into blackness. Ail Ait 
All of a sudden it was night again. 

On the morning of May 8th, 1902, the clocks of St. Pierre ticked on 
toward ten minutes of 8 when they would stop forever. Against a back- 
ground of bright sunshine, a huge column of vapor rose from the cone of 
Mont Pelee. 

A salvo of reports as from heavy artillery. Then, choked by lava boiled 
to white heat by fires in the depths of the earth, Pelee with a terrific 
explosion blew its head off. 

Like a colossal Roman candle it shot out streaks of flame and fiery 
globes. A pall of black smoke rose thousands of feet in the air, darkening 
the heavens. Silhouetted by a red, infernal glare, Pelee flung aloft viscid 
masses which rained incandescent ashes on land and sea. 

Then, jagged and brilliant as the lightning flashes, a fissure opened in 
the flank of the mountain toward St. Pierre. Out of it issued an immense 
cloud which rushed with unbelievable rapidity down on the doomed city 
and the villages of Carbet and Le Precheur. 

In three minutes that searing, suffocating cloud enveloped them, and 
40,000 people died! 

Fernand Clerc, the planter, watched from Mont Parnasse, one mile 
east of St. Pierre, where he had so recently breakfasted. Shrouded in such 
darkness as only the inmost depths of a cavern afford, he reached out 
for the wife and children he could not see and gathered them in blessed 
safety into his arms. But the relatives, the many friends he had left s& 


short a while ago, the American consul and his wife, who had waved him 
a gay good-by them he would never see alive again. . . . 

In that vast brazier which was St. Pierre, Governor Mouttet may have 
lived the instant long enough to realize that Pelee had in truth awakened 
and that eternal sleep was his lot and his wife's and that of all those 
whose flight he had discouraged. . . . 

Down in that deep dungeon cell of his Auguste Ciparis blinked in the 
swift-fallen night. Through the grating blew a current of burning air, 
scorching his flesh. He leaped, writhing in agony and screaming for help. 
No one answered. 

Leaving a blazing city in its wake, the death cloud from the volcano 
rolled over the docks, and the sea, hissing and seething, shrank back 
before it. Aboard the Roraima, Chief Officer Scott lowered his glasses 
precipitately from Pelee. One look at that cloud bearing down like a 
whirlwind and he snatched a tarpaulin from a ventilator and pulled it 
over him. The ship rolled to port, almost on her beam ends, then back 
to starboard. Her funnels and other superstructure and most of her small 
boats were swept off by the mighty blast laden with scalding ashes and 
stone dust. Badly scorched, Scott emerged from his refuge to catch a 
glimpse of the British steamer Roddam plunging by toward the open sea, 
her decks a smoking shambles. Of the other sixteen vessels which had 
been anchored in the roadstead there was no sign. 

Staggering toward the twisted iron wreckage of the bridge, the Chief 
Officer beheld the swaying figure of Captain Muggah. From the hideous, 
blackened mask that had been his face a voice croaked: 

"All hands! Heave up the anchor!" 

All hands! Only Scott, two engineers, and a few members of the black 
gang who had been below responded. In vain Scott scanned the group for 
his son. He never saw the lad again. 

The anchor could not be unshackled. "Save the women and children," 
the captain ordered. During attempts to lower a boat, the captain disap- 
peared. Later he was pulled out of the water in a dying condition. 

Now the Roraima was afire fore and aft. Amid the shrieks and groans 
of dying passengers, Scott and three more able-bodied men fought the 
flames, helped by a few others whose hands, burned raw, made it torture 
to touch anything. Between dousing the fire with bucketfuls from the 
sea, Scott tried to give drinks of fresh water to those who begged pitifully 
for it, though their seared, swollen throats would not let them swallow a 
drop. Tongues lolling, they dragged themselves along the deck, following 
him like dogs. 

When the French cruiser Suchct steamed up to the rescue, the only 


survivors among the passengers were a little girl and her nurse. Twenty- 
eight out of a crew of forty-seven were dead. 

The eyes of all aboard the Suchet turned toward shore. There at the 
foot of a broad, bare pathway, paved by death and destruction down the 
slope of Mont Pelee, lay the utter ruins of the city of St. Pierre. 


Not until the afternoon of May 8th did the devastation of St. Pierre 
cool sufficiently to allow rescuers from Fort-de-France to enter. They 
could find none to rescue except one woman who died soon after she 
was taken from a cellar. 

"St. Pierre, that city this morning alive, full of human souls, is no 
morel" Vicar-General Parel wrote his Bishop. "It lies consumed before 
us, in its windingsheet of smoke and cinders, silent and desolate, a city 
of the dead. We strain our eyes for fleeing inhabitants, for men return- 
ing to bury their lost ones. We see no one! There is no living being left 
in this desert of desolation, framed in a terrifying solitude. In the back- 
ground, when the cloud of smoke and cinders breaks away, the moun- 
tain and its slopes, once so green, stand forth like an Alpine landscape. 
They look as if they were covered with a heavy cloak of snow, and 
through the thickened atmosphere rays of pale sunshine, wan, and 
unknown to our latitudes, illumine this scene with a light that seems 
to belong to the other side of the grave." 

Indeed St. Pierre might have been an ancient town, destroyed in 
some half-forgotten cataclysm and recently partly excavated another 
Pompeii and Herculaneum. Cinders, which had buried its streets six 
feet deep in a few minutes, were as the dust of centuries. Here was the 
same swift extinction Vesuvius had wrought. 

Here was no slow flow of lava. That cloud disgorged by Pelee was a 
superheated hurricane issuing from the depths of the earth at a speed 
of ninety miles an hour. Such was the strength of the blast, it killed 
by concussion and by toppling walls on its victims. The fall of the 
fourteen-foot metal statue of Notre Dame de la Garde Our Lady of 
Safety symbolized the dreadful fact that tens of thousands never had a 
fighting chance for their lives. 

But chiefly the death cloud slew with its lethal content of hot steam 
and dust. So swiftly did it pass that its heat did not always burn all of 
the light tropical clothing from its prey, but once it was inhaled into 
the lungs that was the end. Some had run a few frantic steps; then 
dropped, hands clutched over nose and mouth. Encrusted by cement- 
like ashes, corpses lay fixed in the contorted postures of their last struggle 


replicas of the dead of Vesuvius preserved in the Naples museum. Fire 
had charred others or incinerated them to a heap of bones. A horrible 
spectacle was presented by bodies whose skulls and abdomens had been 
burst by heat and gases. 

People who had been indoors when the cloud descended perished 
where they stood or sat, but the hand of death had marked most of them 
less cruelly. They seemed almost still alive, as each shattered building 
disclosed its denouement. There a girl lay prone, her arms about the 
feet of an image of the Virgin. A man bent with his head thrust into 
a basin from which the water had evaporated. A family was gathered 
around a restaurant table. A child held a doll in her arms; when the 
doll was touched, it crumbled away except for its china eyes. A clerk 
sat at his desk, one hand supporting his chin, the other grasping a pen. 
A baker crouched in the fire pit under his oven. In one room of a 
home a blonde girl in her bathrobe leaned back in a rocking-chair. 
Behind her stood a negro servant who apparently had been combing the 
girl's hair. Another servant had crawled under a sofa. Not far away 
lay the body of a white woman, beautiful as a Greek statue, and like 
many an antique statue headless. 

Mutilated or almost unmarred, shriveled in last agony or seeming only 
to have dropped into a peaceful sleep, lay the legions of the dead. After 
the finding of the dying woman in a cellar, the devastation was searched 
in vain for survivors. 

Then four days after the catastrophe, two negroes walking through the 
wreckage turned gray as they heard faint cries for help issuing from the 
depths of the earth. 

"Who's that?" they shouted when they could speak. " Where are you?" 

Up floated the feeble voice: "I'm down here in the dungeon of the jail. 
Help! Save me! Get me out!" 

They dug down through the debris, broke open the dungeon door, 
and released Auguste Ciparis, the negro criminal. 

Some days later, George Kennan and August F. Jaccaci, American 
journalists arriving to cover the disaster, located Ciparis in a village in the 
country. They secured medical attention for his severe burns, poorly 
cared for as yet, and obtained and authenticated his story. When the 
scorching air penetrated his cell that day, he smelled his own body burn- 
ing but breathed as little as possible during the moment the intense heat 
lasted. Ignorant of what had occurred, not realizing that he was buried 
alive, he slowly starved for four days in his tomb of a cell. His scant 
supply of water was soon gone. Only echoes answered his shouts for 


help. When at last he was heard and freed, Ciparis, given a drink of water, 
managed with some assistance to walk six kilometers to Morne Rouge. 

One who lived where 40,000 died! History records no escape more 


Man, Maker of Wilderness 


From Deserts on the March 


-*L always been. To earth each living thing restores when it dies that 
which has been borrowed to give form and substance to its brief day in 
the sun. From earth, in due course, each new living being receives back 
again a loan of that which sustains life. What is lent by earth has been used 
by countless generations of plants and animals now dead and will be 
required by countless others in the future. In the case of an element such 
as phosphorus, so limited is the supply that if it were not constantly being 
returned to the soil, a single century would be sufficient to produce a 
disastrous reduction in the amount of life. No plant or animal, nor any 
sort of either, can establish permanent right of possession to the materials 
which compose its physical body. 

Left to herself, nature manages these loans and redemptions in not 
unkindly fashion. She maintains a balance which will permit the briefest 
time to elapse between burial and renewal. The turnover of material for 
new generations to use is steady and regular. Wind and water, those twin 
sextons, do their work as gently as may be. Each type of plant and animal, 
so far as it is fit, has its segment of activity and can bring forth its own kind 
to the limits of subsistence. The red rule of tooth and claw is less harsh 
in fact than in seeming. There is a balance in undisturbed nature between 


food and feeder, hunter and prey, so that the resources of the earth are 
never idle. Some plants or animals may seem to dominate the rest, but 
they do so only so long as the general balance is maintained. The whole 
world of living things exists as a series of communities whose order and 
permanence put to shame all but the most successful of human enterprises. 

It is into such an ordered world of nature that primitive man fits as a 
part. A family of savage man, living by the chase and gathering wild 
plants, requires a space of ten to fifty square miles for subsistence. If 
neighbors press too closely, the tomahawk of tribal warfare offers a rude 
but perhaps merciful substitute for starvation. Man in such a stage takes 
what he can get on fairly even terms with the rest of nature. Wind and 
water may strike fear to his heart and even wreak disaster upon him, but 
on the whole their violence is tempered. The forces of nature expend 
themselves beneficently upon the highly developed and well balanced 
forests, grasslands, even desert. To the greatest possible extent the surface 
consists of mellow, absorbent soil, anchored and protected by living plants 
a system buffered against the caprice of the elements, although of course 
subject to slow and orderly change. Bare ground left by the plow will 
have as much soil washed off in ten years as the unbroken prairie will lose 
in four thousand. Even so, soil in the prairie will be forming as fast as, 
or faster than it is lost. 

Living in such a setting, man knows little or nothing of nature's laws, 
yet conforms to them with the perfection over which he has no more choice 
than the oaks and palms, the cats and reptiles around him. Gradually, 
however, and with many halting steps, man has learned enough 
about the immutable laws of cause and effect so that with tools, 
domestic animals, and crops he can speed up the processes of nature 
tremendously along certain lines. The rich Nile Valley can be made to sup- 
port, not one, but one thousand people per square mile, as it does today. 
Cultures develop, cities and commerce flourish, hunger and fear dwindle 
as progress and the conquest of nature expand. Unhappily, nature is not 
so easily thwarted. The old problems of population pressure and tribal 
warfare appear in newer and more horrible guise, with whole nations 
trained for slaughter. And back of it all lies the fact that man has upset 
the balance under which wind and water were beneficial agents of con- 
struction, to release them as twin demons which carve the soil from 
beneath his feet, to hasten the decay and burial of his handiwork. 

Nature is not to be conquered save on her own terms. She is not con- 
ciliated by cleverness or industry in devising means to defeat the operation 
of one of her laws through the workings of another. She is a very busi- 
ness-like old lady, who plays no favorites. Man is welcome to outnumber 


and dominate the other forms of life, provided he can maintain order 
among the relentless forces whose balanced operation he has disturbed. 
But this hard condition is one which, to date, he has scarcely met. His own 
past is full of clear and somber warnings vanished civilizations like dead 
flies in lacquer, buried beneath their own dust and mud. 

For man, who fancies himself the conqueror of it, is at once the maker 
and the victim of the wilderness. Even the dense and hostile jungles 
of the tropics are often the work of his hands. The virgin forest of the 
tropics, as of other climes, is no thicket of scrub and thorn, but a cathe- 
dral of massive, well-spaced giant trees under whose dense canopy the 
alien and tangled rabble of the jungle does not thrive. Order and per- 
manence are here these giants bring forth young after their own kind, 
but only so fast as death and decay break the solid ranks of the elders. 
Let man clear these virgin forests, even convert them into fields, he can 
scarcely keep them. Nature claims them again, and her advance guards 
are the scrambled barriers through which man must chop his way. 

In the early centuries of the present era, while the Roman Empire was 
cracking to pieces, the Mayas built great cities in Central America. Their 
huge pyramids, massive masonry, and elaborate carving are proof of capac- 
ity and leisure. They also indicate that the people who built them prob- 
ably felt a sense of security, permanence, and accomplishment as solid as 
our own. To them the end of their world was no doubt unthinkable save 
as a device of priestly dialectic, or an exercise of the romantic imagination. 
Food there was in abundance, furnished by the maize, cacao, beans, 
and a host of other plants of which southern Mexico is the first home. 
Fields were easily cleared by girdling trees with sharp stone hatchets. You 
can write your name on plate glass with their little jadeite chisels. The 
dead trees were then, as they are today in Yucatan, destroyed by fire, 
and crops were planted in their ashes. 

Yet by the sixth century all of this was abandoned and the Second 
Empire established northward in Yucatan, to last with varying fortunes 
until the Spanish conquest. Pyramids and stonework became the play- 
ground of the jungle, so hidden and bound beneath its knotted mesh 
that painful labor has been required to reveal what is below. Farther 
north in Yucatan, in humble villages, are the modern people, unable to 
read the hieroglyphs of their ancestors, and treasuring only fragments of 
the ancient lore which have survived by word of mouth. There persists 
among these people, for example, a considerable body of knowledge con- 
cerning medicinal plants, their properties and mode of use. But the power 
and glory of the cities is gone. In their place are only ruins and wilderness. 


Their world, once so certain, stable, dependable, and definite, is gone. 
And why? 

Here of course, is a first-rate mystery for modern skill and knowledge 
to unravel. The people were not exterminated, nor their cities taken over 
by an enemy. Plagues may cause temporary migrations, but not the perma- 
nent abandonment of established and prosperous centers. The present 
population to the north has its share of debilitating infections, but its 
ancestors were not too weak or wasted to establish the Second Empire 
after they left the First. Did the climate in the abandoned cities become so 
much more humid that the invasion of dense tropical vegetation could not 
be arrested, while fungous pests, insects, and diseases took increasing toll ? 
This is hard to prove. Were the inhabitants starved out because they had 
no steel tools or draft animals to break the heavy sod which formed over 
their resting fields? Many experts think so. 

Certainly the soil of the wet tropics is very different from the deep rich 
black soil of the prairies. Just as soaking removes salt from a dried 
mackerel, so the nourishing minerals are quickly removed from these soils 
by the abundant water. In the steaming hot climate the plant and animal 
materials which fall upon the ground are quickly rotted, sending gases 
into the air and losing much of what is left, in the pounding, soaking wash 
of the heavy tropical rains. Such organic material as may be present is 
well incinerated when the forest covering is killed and burned, as it was 
by the ancient Mayas, and still is by their descendants. Such a clearing will 
yield a heavy crop for a few seasons, by virtue of the fertilizer in the ashes 
and what little is left in the soil. Presently the yield must decline to the 
point where cultivation is no longer possible. A fresh clearing is made 
and the old one abandoned. Step by step the cultivation proceeds farther 
from the place of beginning. Whether the idle fields, forming an ever 
widening border about the great cities, came to be hidden beneath an 
armor of impenetrable turf or completely ruined by sheet erosion and 
puddling, is immaterial. The restoration of fertility by idleness has proved 
a failure even in temperate climates. It is not a matter of one, or even 
several, human generations, but a process of centuries. The cities of the 
Mayas were doomed by the very system that gave them birth. Man's con- 
quest of nature was an illusion, however brilliant. Like China before the 
Manchu invaders, or Russia in the face of Napoleon, the jungle seemed to 
yield and recede before the Mayas, only to turn with deadly, relentless 
deliberation and strangle them. 

So much for a striking case of failure in the New World. How about 
the Old the cradle of humanity? Here there are striking cases of apparent 
success, long continued, such as eastern China and the Nile Valley. On 


the other hand are many instances of self-destruction as dramatic as that 
of the Mayas for example the buried cities of the Sumerian desert. Let 
us examine both failure and seeming success; after we have done so, we 
shall realize how closely they are interwoven. 

The invention of flocks and herds of domestic animals enable man to 
increase and prevail throughout the great grassy and even the desert 
interior of the Old World. Food and wealth could be moved on the hoof. 
A rough and ready "cowpuncher" psychology was developed as a matter 
of course, combining a certain ruthless capacity for quick action along with 
an aversion to sustained and methodical labor, except for women. Living 
as these people did, in a region where water was none too abundant and 
pasture not always uniform, movement was necessary. Normally this was 
a seasonal migration a round trip like that of the buffalo and other wild 
grazing animals. But from time to time the combination of events brought 
about complete and extensive shifts. 

Where moisture was more abundant, either directly from rain, or 
indirectly through huge rivers, another invention took place. This second 
invention was the cultivation of certain nutritious grasses with unusually 
large fruits the cereals. Probably not far from the mouth of the Yangtze 
River in southeastern China rice was domesticated, while at the eastern 
end of the Mediterranean wheat and barley were put to similar use, both 
in Irak (Mesopotamia) and Egypt. Along with these cereals many other 
plants, such as beans, clover, alfalfa, onions, and the like were grown. 
This invention provided food cheaply and on a hitherto unprecedented 
scale. Domestic animals could now be penned, using their energy to make 
flesh and milk instead of running it off in the continued movements for 
grass and water. Other animals like the cat and dog relieved man of the 
necessity of guarding his stored wealth against the raids of rats and 
robbers. Large animals like the ox and ass saved him the labor of carriage 
and helped in threshing and tillage. The people themselves became 
accustomed to methodical and prolonged labor. They devised means of 
storage and transport and developed commerce. Mechanical contrivances 
proved useful and were encouraged. On the other hand such folk were not 
celebrated for their aggressiveness nor for an itching foot. As they became 
organized and accumulated a surplus of skill and energy they developed 
great cities and other public works, with all adornments. 

The history of early civilization can be written largely in terms of 
these two great inventions in living the pastoral life of the dry interior 
and the settled agriculture of the well-watered regions. Their commerce, 
warfare, and eventual, if imperfect, combination make the Western 
Europe of today. What of their effects upon the land? 


Wherever we turn, to Asia, Europe, or Africa, we shall find the same 
story repeated with an almost mechanical regularity. The net productive- 
ness of the land has been decreased. Fertility has been consumed and soil 
destroyed at a rate far in excess of the capacity of either man or nature to 
replace. The glorious achievements of civilization have been builded on 
borrowed capital to a scale undreamed by the most extravagant of mon- 
archs. And unlike the bonds which statesmen so blithely issue to and 
against their own people, an obligation has piled up which cannot be 
repudiated by the stroke of any man's pen. 

Uniformly the nomads of the interior have crowded their great ranges 
to the limit. The fields may look as green as ever, until the inevitable drier 
years come along. The soil becomes exposed, to be blown away by wind, 
or washed into great flooded rivers during the infrequent, usually tor- 
rential rains. The cycle of erosion gains momentum, at times conveying 
wealth to the farmer downstream in the form of rich black soil, but quite 
as often destroying and burying his means of livelihood beneath a coat 
of sterile mud. 

The reduction of pasture, even with the return of better years, dislocates 
the scheme of things for the owners of flocks and herds. Raids, mass migra- 
tions, discouraged and feeble attempts at agriculture, or, rarely, the 
development of irrigation and dry farming result and history is made. 

Meanwhile, in the more densely settled regions of cereal farming, popu- 
lation pressure demands every resource to maintain yield. So long as rich 
mud is brought downstream in thin layers at regular intervals, the 
valleys yield good returns at the expense of the continental interior. But 
such imperial gifts are hard to control, increasingly so as occupation and 
overgrazing upstream develop. In the course of events farming spreads 
from the valley to the upland. The forests of the upland are stripped, 
both for their own product and for the sake of the ground which they 
occupy. Growing cities need lumber, as well as food. For a time these 
upland forest soils of the moister regions yield good crops, but gradually 
they too are exhausted. Imperceptibly sheet erosion moves them into the 
valleys, with only temporary value to the latter. Soon the rich black valley 
soil is overlain by pale and unproductive material from the uplands. The 
latter may become an abandoned range of gullies, or in rarer cases human 
resourcefulness may come to the fore, and by costly engineering works 
combined with agronomic skill, defer the final tragedy of abandonment. 

Thus have we sketched, in broad strokes to be sure, the story of man's 
destruction upon the face of his own Mother Earth. The story on the older 
continents has been a matter of millennia. In North America it has been 
a matter of not more than three centuries at most generally a matter 


of decades. Mechanical invention plus exuberant vitality have accomplished 
the conquest of a continent with unparalleled speed, but in doing so have 
broken the gentle grip wherein nature holds and controls the forces 
which serve when restrained, destroy when unleashed. 


What Makes the Weather 


-"- the weather, which had been gray and dreary for days and seemed 
as if it were going to stay that way forever, with no breaks in the clouds 
and no indication of a gradual clearing, is now all of a sudden clear and 
sunny and crisp, with a strong northwest wind blowing, and the whole 
world looks newly washed and newly painted. 

"It" has become "fine." Why? How? 

"Something" has cleared the air, you might say. But what? You might 
study out the weather news in the back of your newspaper, and you would 
get it explained to you in terms of barometric highs and lows; but just 
why a rise of barometric pressure should clear the air would still leave you 
puzzled. The honest truth is that the weather has never been explained. 
In school they told you about steam engines or electricity or even about 
really mysterious things, such as gravitation, and they could do it so 
that it made sense to a boy. They told you also about the weather, but 
their explanations failed to explain, and you knew it even then. The lows 
and highs, cyclones and anti-cyclones, the winds that blew around in circles 
all these things were much more puzzling than the weather itself. That 
is why weather has always made only the dullest conversation: there 
simply was no rhyme nor reason to it. 

But now there is. A revolutionary fresh view has uncovered the rhyme 


and reason in the weather. Applied to your particular surprise of that 
morning, it has this to say: 

Thejiir^vhkh^^ is .still warm^ moist, 

and gray this morning ;, but it Jias been pushed fifty or one hundred 
to the south and east of where_^pujiye a _and has been replaced by aj 
of "cold, clear, dry air coming from the north or west. It is as simple as that; 
there is no mysterious "It" in it; just plain physical sense. It is called Air 
Mass Analysis. 

It is based upon the researches and experiments of a. physicist named 
YilhdlII_Bigrkncs, of_Nprway, and though in this particular case it 
seems almostT childishly simple, it is Norway's greatest contribution to 
world culture since Ibsen. Or perhaps because it is simple the rare 
example of a science which in becoming more sophisticated also becomes 
more common sense and easier to understand. It is so new that it hasn't 
yet reached the newspapers, nor the high school curricula, much less the 
common knowledge of the public in general. But the weather bureaus 
of the airlines have worked by it for years, and pilots have to learn it. 
It is indispensable both in commercial flying and in air war; we could fly 
without gasoline, without aluminum, perhaps without radio, but we could 
never do without Bjerknes's Air Mass Analysis. 

You might inquire next whereThat morning's new air came from, and 
just how it got to be cold, dry, and clear. And there you get close to the 
heart of the new weather science, where meteorology turns into honest, 
common-sense geography. 

That air has come from Canada, where it has been quite literally air- 
conditioned. Not all parts ~bf the world have the power to condition air, 
but Canada has. Especially in the fall and winter and early spring, the 
northern part of this continent becomes^ an almost perfectly designed 
mechanical refrigeratoiTTrie "Rocky Mountains in the west keep currents 
of new air from flowing intolBe" regBru And for weeks the air lies still. 
The cool ground, much of it snow-covered; the ice of the frozen lakes; 
plus the perennial stored-up coldness of Hudson's Bay all cool the layer 
of air immediately above them. This means a stabilizing and calming of 
the whole atmosphere all the way up; for cool air is heavy^ and with a 
heavy layer bottommost, there is none_of that upflowing of air, that up- 
welling of moisture-laden heat into the cooler,Tiigh altitude which is the 
mechanism that makes cloud siTHus there may be some low ground fogs 
there, but above them the long nights of those northern latitudes are clear 
and starry, wide open toward the black infinite spaces of the universe; 
and into that black infinity the air gradually radiates whatever warmth it 
may contain from its previous sojourns over other parts of the world* 


The result, after weeks of stagnation, is a huge mass of air that is uni- 
formly ice-cold, dry, and clear. It stretches from the Rocky Mountains 
in the west to Labrador in the east, from the ice wastes of the Arctic to the 
prairies of Minnesota and North Dakota; and the third dimension is the 
most important it is ice-cold from the ground all the way up to the 
stratosphere. It is, in short, a veritable glacier of air. 

That is an air mass. In the jargon of air-faring men, a mass of JPolar 
Canadian' ain" 

When a wave of good, fresh Polar Canadian air sweeps southward into 
the United States it happens almost rhythmically every few days you 
don't need a barometer to tell you so. There is nothing subtle, theoretical, 
or scientific about it. You can see and feel the air itself and even hear it. It 
comes surging out of a blue-green sky across the Dakptas, shaking the 
hangar doors, whistling in the grassTputting those red-checkered thick 
woolen jackets on the men, and lighting the stoves in the houses. It flows 
southward down the Mississippi Valley as a cold wave in winter, or as 
relief from a heat wave in summer, blowing as a northwest wind with 
small white hurrying clouds in it. In winter it may sweep southward as 
far as Tennessee and the Carolinas, bringing frosts with brilliantly^clear 
skies, making the darkies shiver in their drafty cabins, and producing a 
wave of deaths by pneumonia. Sometimes it even reaches the Texas Gulf 
Coast; then it is locally called a norther, and the cows at night crowd for 
warmth around the gas flares in the oil fields. A duck hunter dies of 
exposure in the coastal swamps. A lively outbreak of Polar Canadian air 
may reach down into Florida, damage the orange crops, and embarrass 
local Chambers of Commerce. And deep outbreaks have been observed to 
drive all the way down to Central America, where they are feared as a 
fierce wind called the Tehuantepecer. 

Polar Canadian is only one of many sorts of air. To put it in the 
unprecise language of the layman, the great Norwegian discovery is that 
air must always be of some distinct type: that it is never simply air but 
always conditioned and flavored. What we call weather is caused by 
gigantic waves in the air ocean which flood whole countries and conti- 
nents for days at a stretch with one sort of air or another. And there is 
nothing theoretical about any of these various sorts of air. 

Each kind is easily seen and felt and sniffed, and is, in fact, fairly 
familiar even to the city dweller, although he may not realize it. Each has 
its own peculiar characteristics, its own warmth or coolness, dampness or 
dryness, milkiness or clearness. Each has its own quality of light. In each, 
smoke behaves differently as it pours from the chimneys: in some kinds 
of air it creeps lazily, in some it bubbles away, in some it floats in layers- 


That is largely why the connoisseur can distinguish different types of air 
by smell. 

Each type of air combines those qualities into an "atmosphere" of its 
own. Each makes an entirely different sort of day. In fact, what sort of day 
it is raw, oppressive, balmy, dull, a "spring" day depends almost entirely 
upon the sort of air that lies over your particular section of the country at 
that particular time. 

And if you tried to describe the day in the old-fashioned terms wind 
direction and velocity, humidity, state of the sky you could never quite 
express its particular weather; but you can by naming the sort of air. An 
airplane pilot, once he is trained in the new weather thinking, can get 
quite impatient with the attempts of novelists, for instance, to describe 
weather. "Why don't you say it was Polar Canadian air and get on with 
your story?" 

And if you are a connoisseur of airs just about the first thing you will 
note every morning is something like, "Ah, Caribbean air to-day"; or if 
you are really a judge you can make statements as detailed as, "Saskatch- 
ewan air, slightly flavored by the Great Lakes." 

For just as wines do, the airs take their names and their flavors from 
the regions where they have matured. Of the seven airs that make up the 
American weather, one is quite rare and somewhat mysterious. It is 
known by the peculiarly wine-like name of Sec Superieur. It is believed 
to be of tropical origin, but it comes to this continent after spending weeks 
in the stratosphere somewhere above the Galapagos Islands. It is usually 
found only high aloft, and interests pilots more than farmers. But once 
in a while a tongue of it reaches the ground as hot, extremely dry, very 
clear weather; and wherever it licks there is a drought. 

The other six airs all come from perfectly earthly places, though far- 
away ones. The easiest to recognize, the liveliest, is Polar Canadian. Its 
opposite number in the American sky is Trnpicd JGlilf ^ r Trnpirrrf 
AtlagtJ. (<J aiirr-the steamy, warm air of the Eastern and MidvE&jrn 
summer^ the kind Hiaf "comes alHTsotfftTfl^ starts people to 

taflungabout heat and humidity, the kind that is sometimes so steamy that 
it leaves you in doubt as to whether the sky means to be blue or overcast. 
This air is brewed of hot sun and warm sea water in the Caribbean 
region. The mechanism that does the air conditioning in this case is 
mostly the daily afternoon thunderstorm which carries moisture and heat 
high aloft in it. 

Not quite SQ obvious is the origin of the moist, silvery, coolicbaununer^ 
cool-in-winter air that dominates the wcathciL^-Sga.tdf It jscallej Polar 
PaciBcpand it is a trick product. Its basic characteristics have been 


acquired over Siberia and it is cold and dry; but on its way across the 
Pacific its lower five to ten thousand feet have been warmed up and 
moistened. Sometimes such air comes straight across, reaching land in a 
couple of days. Sometimes it hangs over the water for a week, and it 
takes a good weatherman to predict just what sort of weather it will 

Its counterpart is a flavor known as Tropical Pacific. That is the air they 
sell to tourists in Southern California. It is really just plain South Seas 
air, though the story here too is not as clear-cut as it might be. 

A clear-cut type is Polar Atlaruic^ir. It sometimes blows down the New 
England coast as a nor'easter, cold, rainy, with low clouds. It is simply 
a chunk of the Grand Banks off Newfoundland gone traveling, and you 
can almost smell the sea. 

And one air that every tourist notices in the Southwest is Tropical Con-' 
tinental. Its source region is the deserts of Arizona and Mexico. It is dry 
and hot and licks up moisture so greedily that it makes water feel on youf 
skin as chilly as if it were gasoline. It is not an important one for America, 
though its European counterpart, Saharan air, is important for Europe. 
Oklahoma, Colorado, and Kansas are as far as it ever gets; but even so, 
a few extra outbreaks of it per year, and we have a dust bowl. 


The air mass idea is simple. As great ideas often do, the air mass idea 
makes you feel that you have known it right along. And in a vague way, 
you have. Take, for example, that half-brag, half-complaint of the Texans 
that there is nothing between Texas and the North Pole to keep out those 
northers but a barbed wire fence: it contains the kernel of the whole idea 
the invading air mass but only in a fooling way. Or take the manner in 
which the Mediterranean people have always given definite names to cer- 
tain winds (boreas, sirocco, mistral) that blow hot or cold, dry or moist, 
across their roofs. They are names, however, without the larger view. In 
creative literature such things as a cold front passage the sudden arrival 
of a cold air mass have been described several times quite accurately, 
but always as a local spectacle, with the key thought missing. 

Actually it took genius to see it. For air is a mercurial fluid, bubbly, 
changeable; it is as full of hidden energies as dynamite; it can assume the 
most unexpected appearances. There are days, to be sure, when the air 
virtually advertises its origin. Offhand, you might say that on perhaps half 
the days of the year it does. But there are also days when it$ appearance is 
altogether misleading. 

Take, for example, the amazing metamorphosis that happens to 


Tropical Gulf air when it flows northward across the United States in 
winter. It starts out from among the Islands looking blue and sunny and 
like an everlasting summer afternoon. When it arrives over the northern 
United States that same air appears as a dark-gray shapeless, drizzling over- 
cast, and in the office buildings of New York and Chicago the electric 
lights are on throughout what is considered a shivery winter day. It is 
still the same air; if we could mix a pink dye into the air, as geographers 
sometimes mix dyes into rivers to trace the flow of water, a cloud of pink 
air would have traveled from Trinidad to New York. It has hardly 
changed at all its actual contents of heat and water; but as far as its 
appearance and its feel are concerned its "weather" value a few days 
of northward traveling have reversed it almost into a photographic nega- 
tive of itself. 

What happens in this particular case and it accounts for half our winter 
days is simply that the cool ground of the wintry continent chills this 
moist, warm air mass chills it just a little, not enough to change its 
fundamental character, and not all the way up into its upper levels, but in 
its bottommost Ir.yer and that only just enough to make it condense out 
some of its abundant moisture in the form of visible clouds; it is quite 
similar to the effect of a cold window pane on the air of a well-heated, 
comfortable room there is wetness and cooling right at the window, but 
the bulk of the room's air is not affected. 

Perhaps the oddest example of this is the trick by which Polar Pacific 
air, striking the United States at Seattle, cool and moist, arrives in eastern 
Montana and the Dakotas as a chinook, a hot, dry, snow-melting wind. 

As Polar Pacific air flows up the slopes of the Sierras and the Cascades 
it is lifted ten thousand feet into the thinner air of higher altitude. By one 
law of physics the lifting should chill the air through release of pressure. 
If you have ever bled excess pressure out of your tires you know this cool- 
ing by release of pressure you know how ice-cold the air comes hissing 
out. But in this case, by a different law of physics, Polar Pacific reacts by 
cooling only moderately; then it starts condensing out its moisture and 
thereby protecting its warmth; hence the tremendous snowfalls of the 
sierras, the giant redwoods, the streams that irrigate California ranches. 

Once across the Cascades and the Sierras, the air flows down the eastern 
slopes. In descending it comes under pressure and therefore heats up, just 
as air heats up in a tire pump. Warmed, the air increases its capacity to 
hold moisture; it becomes relatively drier thus this air sucks back its 
own clouds into invisible form. When it arrives over the Columbia Basin, 
or the country round Reno, or Owens Valley, it is regular desert air 
warm, very clear, and very dry. That is why the western deserts are 


where they are. Flowing on eastward, it comes against another hump, 
the Continental Divide and the Rockies. Here the whole process repeats 
itself. Again the air is lifted and should become ice-cold; again it merely 
cools moderately, clouds up, and drops its remaining moisture to protect 
its warmth; hence the lush greenery of Coeur d'Alene, the pine forests 
of New Mexico. Finally, as the air flows down the eastern slope of the 
Rockies, compression heats it once more, as in the bicycle pump. Twice 
on the way up it has dropped moisture and thus failed to cool; twice 
on the way down it has been heated : it is now extremely dry, and twenty 
degrees warmer than it was at Seattle. That is the chinook, a wind 
manufactured of exactly the sort of principles that work in air-condition- 
ing machinery, and a good example of the trickery of air masses. But it 
is still a simple thing; it is still one actual physically identical mass of air 
that you are following. It you had put pink smoke into it at Seattle, pink 
smoke would have arrived in South Dakota. 

That is how the air mass concept explains all sorts of weather detail: 
the various kinds of rain showery or steady; the many types of cloud 
low or high, solid or broken, layered or towering; thunderstorms; fog. 
An air mass, thus-and-thus conditioned, will react differently as it flows 
over the dry plains, the freshly plowed cotton fields, the cool lakes, the 
hot pavements, the Rocky Mountains of the United States. 

An airplane pilot's weather sense consists largely of guessing the exact 
manner in which a given sort of air will behave along his route. Tropical 
Gulf in summer over Alabama? Better not get caught in the middle after- 
noon with a low fuel reserve. We shall have to detour around many 
thunderstorms. The details are as multifarious as geography itself, but 
much of it has by now been put into the manuals, and the pilot memorizes 
such items as these: 

Canadian air that passes over the Great Lakes in winter is moistened 
and warmed in its lower layers and becomes highly unstable. When such 
air hits the rolling country of western Pennsylvania and New York and 
the ridges of the Appalachians the hills have a sort of "trigger action" 
and cause snow flurries or rain squalls with very low ceilings and visibility. 

In summer, Canadian air that flows into New England, dried, without 
passing over the Great Lakes, will be extremely clear and extremely 

Tropical Gulf over the South forms patchy ground fog just before 
sunrise that will persist for two or three hours. 

As Polar Pacific air moves southward along the Pacific Coast it forms 
a layer of "high fog." 


In Colorado and Nebraska fresh arriving Canadian air frequently shows 
as a dust storm. 

Given two types of country underneath, one kind of air can produce 
two sorts oi weather only a few miles apart. Tropical Atlantic air, for 
instance, appears over the hills of New England as hot and summery 
weather, slightly hazy, inclined toward afternoon thunderstorms. A few 
miles of? the coast the same air appears as low banks of fog. That is 
because the granite and the woods are warmed all through, and actually 
a little warmer than Tropical Gulf air itself, at least during the day; 
while the ocean is much colder than the air, and cools it. 

Again, one kind of country can have opposite effects on two different 
types of air. For example, the farms of the Middle West in the spring 
when the frost is just out of the ground: that sort of country feels cool 
to Tropical Gulf air that has flowed up the Mississippi Valley. The bottom 
layers of that warm moist air are chilled and thus the whole air mass is 
stabilized. It will stay nicely in layers; the clouds will form a flat, level 
overcast; smoke will spread and hover as a pall. But to a mass of freshly 
broken-out Canadian air that sort of country feels warm. The air in 
immediate contact with the ground is warmed, and the whole mass 
becomes bottom-light and unstable. 

And that means action: a commotion much like the boiling of water 
on a huge scale and in slow motion. The warmed air floats away upward 
to the colder air aloft, forming bubbles of rising air, hundreds of feet 
in diameter, that are really hot-air balloons without a skin. 

Those rising chunks of air are felt by fliers as bumps. When the ship 
flies into one it gets an upward jolt; when it flies out again it gets a down- 
ward jolt. They are what makes it possible to fly a glider, even over flat 
country; all you have to do is to find one of those bubbles, stay in it by 
circling in a tight turn, and let it carry you aloft. 

The clear air, the tremendous visibility of such a day is itself the result 
of instability: the rising bubbles carry away the dust, the haze, the indus- 
trial smoke. The air is always roughest on one of those crisp, clear, newly 
washed days. If the rising air gets high enough it makes cumulus clouds, 
those characteristic, towering, puffy good-weather clouds. That sort of 
cloud is nothing but a puff of upward wind become visible. The rise 
has cooled the air and made its water vapor visible. Soaring pilots seek 
to get underneath a cumulus cloud there is sure to be a lively upflow 
there. Sometimes, in really unstable air, the rising of the air reaches 
hurricane velocities. We call that a thunderstorm, but the lightning and 
thunder are only by-products of the thing. The thing itself is simply a 
vicious, explosive upsurging of air: the wind in thunderstorms blows 


sixty to one hundred miles per hour straight up! The most daring of 
soaring pilots have flown into thunderstorms and have been sucked up 
almost to the stratosphere. 

The weatherman, unlike the pilot, need not guess. He has got a slide 
rule; he has got the laws of gases, Charles's Law, Boyle's Law, Buys 
Ballot's Law at his fingertips. He has studied thermodynamics, and he 
has got a new device that is the biggest thing in weather science since 
Torricelli invented the barometer the radio sonde with which he can 
take soundings of the upper air, find out just how moisture and tempera- 
ture conditions are aloft, just how stable or unstable the air will be, at 
what level the clouds will form, and of what type they will be. 

Radio sondes go up in the dead of night from a dozen airports all over 
the continent. The radio sonde looks like a box of candy, being a small 
carton wrapped in tinfoil; but it is actually a radio transmitter coupled 
to a thermometer and a moisture-meter. It is hung on a small parachute 
which is hitched to a balloon. It takes perhaps an hour for the balloon 
to reach the stratosphere, and all the time it signals its own readings in 
a strange, quacky voice, half Donald Duck, half voice from the beyond. 
Then it stops. You know that the balloon has burst, the parachute is 
letting the instrument down gently. 

The next morning some farm boy finds the shiny thing in a field, with 
a notice attached offering a reward for mailing it back to the weather 

Also the next morning a man in Los Angeles paces up and down his 
office, scanning the wall where last night's upper-air soundings are tacked 
up. Emitting heavy cigar smoke and not even looking out of the window, 
he dictates a weather forecast for the transcontinental airway as far east 
as Salt Lake City, a forecast that goes into such detail that you sometimes 
think he is trying to show off. 


With the air mass idea as a key, you can make more sense out of the 
weather than the professional weatherman could before Bjerknes; and 
even if you don't understand Boyle's Law and all the intricate physics 
of the atmosphere, you can do a quite respectable job of forecasting. 

It goes like this : suppose you are deep in Caribbean air. You will have 
"air mass weather": a whole series of days of the typical sort that goes 
with that particular type of air when it overlies your particular section of 
the country in that particular season. There will be all sorts of minor 
changes; there will be a daily cycle of weather, clouds, perhaps thunder- 
storms, or showers; but essentially the weather will be the same day aftet 


day. Any real change in weather can come only as an incursion of a new 
air mass probably Polar Canadian. 

And when that air mass comes you will know it. New air rarely comes 
gently, gradually, by imperceptible degrees; almost always the new air 
mass advances into the old one with a clear-cut, sharply defined forward 
front. Where two air masses adjoin each other you may in half an hour's 
driving in five minutes' flying change your entire weather, travel 
from moist, muggy, cloudy weather into clear, cool, sunny weather. 
That clear-cut boundary is exactly what makes an air mass a distinct 
entity which you can plot on a map and say, "Here it begins; here it 
ends"; these sharp boundaries of the air masses are called "fronts" and 
are a discovery as important as the air mass itself. 

You are watching, then, for a "cold front," the forward edge of an 
advancing mass of cold air. You will get almost no advance warning. 
You will see the cold air mass only when it is practically upon you. But 
you know that sooner or later it must come, and that it will come from 
the northwest. Thus, an occasional long-distance call will be enough- 
Suppose you are in Pittsburgh, with a moist, warm southwest wind: the 
bare news that Chicago has a northerly wind might be enough of a clue.. 
If you knew also that Chicago was twenty degrees cooler you would be 
certain that a cold air mass had swamped Chicago and was now presum- 
ably on its way to Pittsburgh, traveling presumably at something like 
30 m.p.h. You could guess the time of arrival of its forward front within 
a few hours. That is why the most innocent weather reports are now 
so secret; why the British censor suppresses snow flurries in Scotland;, 
why a submarine in the Atlantic would love to know merely the wind 
direction and temperature at, say, Columbus, Ohio; why the Gestapo* 
had that weather station in Greenland. 

Knowing that a cold front is coming, you know what kind of weather 
to expect; though some cold fronts are extremely fierce, and others quite 
gentle (noticeable only if you watch for them), the type is always the 
same. It is all in the book Bjerknes described it and even drew pictures 
of it. It was the advance of such a cold front which occurred while you 
slept that night before you awoke to find the world fresh and newly 

Cold air is heavy; as polar air plows into a region occupied by tropical 
air it underruns; it gets underneath the warm air and lifts it up even 
as it pushes it back. A cold front acts physically like a cowcatcher. 

Seen from the ground, the sequence of events is this: an hour or two- 
before the cold front arrives the clouds in the sky become confused,, 
somewhat like a herd of cattle that smells the coyotes; but you observe- 


that by intuition rather than by measurable signs. Apart from that, there 
are no advance signs. The wind will be southerly to the last, and the air 
warm and moist. 

Big cumulus clouds build up all around, some of them with dark 
bases, showers, and in summer thunder and lightning that is the warm 
moist air going aloft. A dark bank of solid cloud appears in the north- 
west, and though the wind is still southerly, this bank keeps building up 
and coming nearer: it is the actual forward edge of the advancing cold 
air. When it arrives there is a cloudburst. Then the cold air comes sweep- 
ing in from the northwest with vicious gusts. This is the squall that cap- 
sizes sailboats and uproots trees, flattens forests and unroofs houses. 

The whole commotion probably is over in half an hour. The wind eases 
up, though it is still cool and northwesterly, the rain ceases, the clouds 
break and new sky shows: the front has passed, the cold air mass has 

The weatherman can calculate these things too. He has watched and 
sounded out each of the two air masses for days or even weeks, ever 
since it moved into his ken somewhere on the outskirts of the American 
world. Thus an airline weatherman may look at a temperature-moisture 
graph and say, "This is dynamite. This air will be stable enough as long 
as it isn't disturbed. But wait till some cold air gets underneath this and 
starts lifting it. This stuff is going to go crazy." 

In making your own guess you would take the same chance that the 
weatherman takes every morning that you might be right and yet get 
an error chalked up against you. Suppose the Chicago weatherman, 
seeing a cold front approach, forecasts thunderstorms. One thunderstorm 
passes north of the city, disturbing the 30,000 inhabitants of Waukegan. 
Another big one passes south of Chicago, across farms just south of Ham- 
mond, Ind., affecting another 30,000 people. None happens to hit Chicago 
itself, with its 3 million people. On a per capita basis, the weatherman was 
98 per cent wrong! Actually he was right. 

Now you are in the cold air mass, and you can reasonably expect "air 
mass weather" for a while rather than "frontal" weather; />., a whole 
series of whatever sort of day goes with Canadian air in your particular 
section of the country at that particular season. 

Any real change in the weather nous can again come only with an 
incursion of a new and different air mass and now that will probably 
mean tropical maritime air of the Gulf kind. To forecast that invasion 
is no trick at all: you can see the forward front of the warm air mass 
in the sky several days before it sweeps in on the ground. Warm air is 
light. As Caribbean air advances into a region occupied by Canadian air 


it produces a pattern that is the exact opposite of the cold front. The 
warm front overhangs forward, overruns the cold air; the warm air mass 
may appear high above Boston when at ground level it is just invading 
Richmond, Va. 

Again the sequence of events is predictable Bjerknes drew the picture. 
It is the approaching warm front that makes for "bad" weather, for rain 
of the steady, rather than the showery kind, for low ceilings. 

Consider a warm front on the morning when its foot is near Rich- 
mond and its top over Boston. Boston that morning sees streaks of cirrus 
in its sky "mares' tails," the white, feathery, diaphanous cloud arranged 
in filaments and bands, that is so unsubstantial that the sun shines clear 
through it and you are hardly conscious of it as a cloud and actually it 
doesn't consist of water droplets, as do most clouds, but of ice crystals. 
New Haven the same morning has the same kind of cloud, but slightly 
thicker, more nearly as a solid, milky layer. New York that same morning 
sees the warm air as a gray solid overcast at 8,000 feet. Philadelphia has 
the same sort of cloud at 5,000, with steady rain. Washington has 1,500 
feet, rain. Quantico and Richmond report fog, and all airplanes are 
grounded. Raleigh, N.C., has clearing weather, the wind has shifted that 
morning to the southwest, and it is getting hot and humid there. Raleigh 
would be definitely behind the front, well in the warm air mass itself. 

By nightfall Boston has the weather that was New Haven's in the 
morning. The moon, seen through a milky sheet of cirrus clouds, has a 
halo: "There is going to be rain." New Haven that night has New York's 
weather of that morning; New York has Philadelphia's; and so on down 
the line the whole front has advanced one hundred miles. In fore- 
casting the weather for Boston it is safe to guess that Boston will get in 
succession New Haven weather, New York weather, Philadelphia, 
Washington, Richmond weather and finally Raleigh weather in a 
sequence that should take two or three days: steady lowering clouds, 
rainy periods, some fog followed finally by a wind shift to the southwest, 
and rapid breaking of clouds, and much warmer, very humid weather. 

And then the cycle begins all over. You are then deep in Caribbean 
air again. You will have Caribbean air mass weather, and your weather eye 
had better be cocked northwest to watch for the first signs of polar air. 


There is a rhythm, then, in the weather, or at least a sort of rhyme, 
a repetitive sequence. All those folk rules that attribute weather changes 
to the phases of the moon, or to some other simple periodicity ("If the 
weather is O.K. on Friday, it is sure to rain over the week-end") are 


not so far from the mark after all. The rhythm does not work in terms 
of rain or shine; but it does work in terms of air masses; and thus, 
indirectly and loosely, through the tricky physics of the air, it governs 
also the actual weather. 

What makes the air masses move, and what makes them move 
rhythmically that is the crowning one of the great Norwegian discov- 
eries. Some of it had long been known. It was understood that the motive 
power is the sun. By heating the tropics and leaving the polar region 
cold, it sets up a worldwide circulation of air, poleward at high altitude, 
equatorward at lower levels. It was understood that this simple circulation 
is complicated by many other factors such as the monsoon effect: conti- 
nents heat up in summer and draw air in from over the ocean, in winter 
they cool and air flows out over the ocean; there was the baffling Coriolis 
Force that makes all moving things (on the Northern Hemisphere) 
curve to the right. In everyday life we don't notice it, but some geogra- 
phers hold that it affects the flow of rivers, and artillerymen make allow- 
ance for it: a long-range gun is always aimed at a spot hundreds of yards 
to the left of the target. The monsoons and the Coriolis Force between 
them break up the simple pole-to-equator-to-pole flow of the air into a 
worldwide complicated system of interlocking "wheels" huge eddies 
that show variously as tradewinds, calm belts, prevailing westerlies. 
Charts have been drawn of the air ocean's currents showing how air is 
piled up over some parts of the world, rushed away from others. 

But it remained for the Norwegians to discover the polar front 
perhaps the last-discovered geographical thing on this earth. Bjerknes 
himself first saw it that the worldwide air circulation keeps piling up 
new masses of polar air in the north and pressing them southward; it 
keeps piling up new masses of tropical air in the south, pressing them 
northward; and thus forever keeps forcing tropical and polar air masses 
against each other along a front; that the demarcation line between 
tropical air masses, pressing northward, and polar air masses, pressing 
southward, runs clear around the world: through North America and 
across the Atlantic, through Europe and across Siberia, through Japan 
and across the Pacific. The polar front is clear-cut in some places, tends 
to wash out in others; but it always reestablishes itself. 

In summer, the polar front runs across North America north of the 
Great Lakes; in winter, it takes up a position across the United States. 
Wherever it is, it keeps advancing southward, retreating northward, 
much like a battlefront. And all the cold fronts and warm fronts are 
but sections of this greater front. 

The rhythmical flowing of the air masses, the Norwegians discovered, 


is simply this wave action along the polar front. Like all the rest of the 
modern weather concepts, this one becomes common sense, almost self- 
evident the moment you realize that air is stuff, a real fluid that has 
density and weight. Except that it occurs on a scale of unhuman mag- 
nitude, wave action along the polar front is almost exactly the same thing 
as waves on a lake. 

In a lake, a dense, heavy fluid the water lies underneath a thin, light 
fluid the air and the result is that rhythmical welling up and down 
of the lake-surface that we call waves. Along the polar front, a dense, 
heavy fluid, the polar air, lies to the north of a thin, lighter fluid, the 
tropical air; the result is a rhythmical welling southward and northward 
of the two kinds of air. When a water wave rolls across a lake its first 
manifestation is a downward bulging of the water, then an upward 
surging. When a wave occurs in the polar front it appears first as a 
northward surging of warm air, and that means all the phenomena of a 
warm front. Then, in the rhythmical backswing, comes the southward 
surging of cold air, and that means all the phenomena of a cold front. 

These waves are bigger than the imagination can easily encompass. 
They measure 500 to 1,000 miles from crest to crest. When tropical air 
surges northward it will wash to the edge of the Arctic; when Polar air 
surges southward it reaches down into the tropics. Such a wave will 
travel along the polar front all the way from somewhere out in the 
Pacific, across the United States and out to the Atlantic; that is the 
meteorological action which underlies the recent novel Storm by George 
Stewart: the progress of a wave along the polar front. 

So similar are these air waves to the air-water waves of a lake that there 
are even whitecaps and breakers. What we call a whitecap or a breaker 
is a whirling together of air and water into a white foam. In the great 
waves along the polar front the same toppling-over can occur: warm and 
cold air sometimes wheel around each other, underrun and overrun each 
other, in a complicated, spiral pattern. 

And that is where the old papery weather science of the schoolbooks 
merges with the realistic observations of the Norwegians. You remember 
about those Lows that were traveling across the weather map and brought 
with them bad weather. You know how a dropping barometer has always 
indicated the coming of bad weather though we have never quite 
known why. 

Now it turns out that the barometric low is nothing but one of those 
toppling-over waves in the polar front or rather, it is the way in which 
the spiral surging of the air masses affects the barometers. Look at the 
Middle West when it is being swept by one of those waves, take a reading 


of everybody's barometer, and you get the typical low. Look at it when 
a low is centered, watch the kinds of air that are flowing there, the wind 
directions, the temperatures and humidities and you find that a low has 
a definite internal structure: the typical wave pattern, with a warm air 
mass going north and a cold air mass going south, both phases of the same 

Barometric pressures turn out to be not the cause of the weather, but 
simply a result, a rather unimportant secondary symptom of it. What 
weather actually is the Norwegians have made clear. It is the wave 
action of the air ocean. 




"I do not know what 1 may appear to the world, but to myself I seem 
to have been only like a boy playing on the sea-shore, and diverting myself 
in now and then finding a smoother pebble and a prettier shell than or- 
dinary, whilst the great ocean of truth lay all undiscovered before me." 
Sir Isaac Newton 

"If I have seen farther than Descartes, it is by standing on the shoul- 
ders of giants." Sir Isaac Newton 

"Newton was the greatest genius that ever existed and the most for- 
tunate, for we cannot find more than once a system of the world to estab- 
lish." Lagrange 

"There may have been minds as happily constituted as his for the 
cultivation of pure mathematical science; there may have been minds 
as happily constituted for the cultivation of science purely experimental; 
but in no other mind have the demonstrative faculty and the inductive 
faculty co-existed in such supreme excellence and perfect harmony." 
Lord Macaulay 

"Taking mathematics from the beginning of the world to the time 
when Newton lived, what he had done was much the better half." 

"Let Men Rejoice that so great a glory of the human race has ap- 
peared." Inscription on Westminster Tablet 

"The law of gravitation is indisputably and incomparably the greatest 
scientific discovery ever made, whether we look at the advance which it 
involved, the extent of truth disclosed, or the fundamental and satisfac- 
tory nature of this truth." William Whewell 

"Newton's greatest direct contribution to optics, appears to be the 
discovery and explanation of the nature of color. He certainly laid the 



broad foundation upon which spectrum analysis rests, and out of this has 
come the new science of spectroscopy which is the most delicate and 
powerful method for the investigation of the structure of matter. Dayton 
C. Miller 

"On the day of Cromwell's death, when Newton was sixteen, a great 
storm raged all over England. He used to say, in his old age, that on that 
day he made his first purely scientific experiment. To ascertain the force 
of the wind, he first jumped with the wind and then against it, and by 
comparing these distances with the extent of his own jump on a calm 
day, he was enabled to compute the force of the storm. When the wind 
blew thereafter, he used to say it was so many feet strong. fames Parton 

"His carriage was very meek, sedate and humble, never seemingly 
angry, of profound thought, his countenance mild, pleasant and comely. 
I cannot say I ever saw him laugh but once, which put me in mind of 
the Ephesian philosopher, who laughed only once in his lifetime, to see 
an ass eating thistles when plenty of grass was by. He always kept close 
to his studies, very rarely went visiting anrJ had few visitors. I never 
knew him to take any recreation or pastime either in riding out to take 
the air, walking, bowling, or any other exercise whatever, thinking all 
hours lost that were not spent in his studies, to which he kept so close 
that he seldom left his chamber except at term time, when he read in 
the schools as Lucasianus Professor, where so few went to hear him, and 
fewer that understood him, that ofttimes he did in a manner, for want 
of hearers read to the walls. Foreigners he received with a great deal of 
freedom, candour, and respect. When invited to a treat, which was very 
seldom, he used to return it very handsomely, and with much satisfac- 
tion to himself. So intent, so serious upon his studies, that he ate very 
sparingly, nay, ofttimes he has forgot to eat at all, so that, going into his 
chamber, I have found his mess untouched, of which, when I have re- 
minded him, he would reply 'Have I?' and then making to the table 
would eat a bite or two standing, for I cannot say I ever saw him sit at 
table by himself. He very rarely went to bed till two or three of the 
clock, sometimes not until five or six, lying about four or five hours, 
especially at spring and fall of the leaf, at which times he used to em- 
ploy about six weeks in his elaboratory, the fires scarcely going out 
either night or day; he sitting up one night and I another till he had fin- 
ished his chemical experiments, in the performance of which he was the 
most accurate, strict, exact. What his aim might be I was not able to 
penetrate into, but his pains, his diligence at these set times made me think 
he aimed at something beyond the reach of human art and industry. I 


cannot say I ever saw him drink either wine, ale or beer, excepting at 
meals and then but very sparingly. He very rarely went to dine in the 
hall, except on some public days, and then if he has not been minded, 
would go very carelessly, with shoes down at heels, stockings untied, sur- 
plice on, and his head scarcely combed. 

His elaboratory was well furnished with chemical materials, as bodies, 
receivers, heads, crucibles, etc. which was made very litle use of, the 
crucibles excepted, in which he fused his metals; he would sometimes, tho' 
very seldom, look into an old mouldy book which lay in his elaboratory, 
I think it was titled Agricola de Metallis, the transmuting of metals being 
his chief design, for which purpose antimony was a great ingredient. He 
has sometimes taken a turn or two, has made a sudden stand, turn'd 
himself about, run up the stairs like another Archimedes, with an Eureka 
fall to write on his desk standing without giving himself the leisure to 
draw a chair to sit down on. He would with great acuteness answer a 
question, but would very seldom start one. Dr. Boerhave, in some of his 
writings, speaking of Sir Isaac: 'That man/ says he, "comprehends as 
much as all mankind besides.' Humphrey Newton 

"When we review his life, his idiosyncrasies, his periods of contrast, 
and his doubts and ambitions and desire for place, may we not take some 
pleasure in thinking of him as a man a man like most other men save 
in one particular he had genius a greater touch of divinity than comes 
to the rest of us? "David Eugene Smith 





of the heavens and of our sea by the power of gravity, but have 
not yet assigned the cause of this power. This is certain, that it must 
proceed from a cause that penetrates to the very centres of the sun and 
planets, without suffering the least diminution of its force; that operates 
not according to the quantity of the surfaces of the particles upon which 
it acts (as mechanical causes used to do), but according to the quantity 
of the solid matter which they contain, and propagates its virtue on all 
sides to immense distances, decreasing always in the duplicate propor- 
tions of the distances. Gravitation towards the sun is made up out of the 
gravitations towards the several particles of which the body of the sun 
is composed; and in receding from the sun decreases accurately in the 
duplicate proportion of the distances as far as the orb of Saturn, as evi- 
dently appears from the quiescence of the aphelions of the planets; nay, 
and even to the remotest aphelions of the comets, if these aphelions are 
also quiescent. But hitherto I have not been able to discover the cause 
of those properties of gravity from phaenomena, and I frame no hypoth- 
eses; for whatever is not deduced from the phaenomena is to be called 
an hypothesis; and hypotheses, whether metaphysical or physical, whether 
of occult qualities or mechanical, have no place in experimental phi- 
losophy. In this philosophy particular propositions are inferred from the 
phaenomena, and afterwards rendered general by induction. Thus it was 
that the impenetrability, the mobility, and the impulsive force of bodies, 
and the laws of motion and gravitation were discovered. And to us it is 
enough that gravity does really exist, and act according to the laws which 
we have explained, and abundantly serves to account for all the motions 
of the celestial bodies, and of our sea. 

From Newton's "Principia" edition of 1726 



Law I. Every body perseveres in its state of rest, or of uniform motion 
in a right line, unless it is compelled to change that state by force im- 
pressed thereon. 

Projectiles persevere in their motions, so far as they are not retarded 
by the resistance of the air, or impelled downwards by the force of gravity. 
A top, whose parts by their cohesion are perpetually drawn aside from 
rectilinear motions, does not cease its rotation, otherwise than as it is 
retarded by the air. The greater bodies of the planets and comets, meet- 
ing with less resistance in more free spaces, preserve their motions both 
progressive and circular for a much longer time. 

Law II. The alteration of motion is ever proportional to the motive 
force impressed '; and is made in the direction of the right line in which 
that force is impressed. 

If any force generates a motion, a double force will generate double 
the motion, a triple force triple the motion, whether that force be im- 
pressed altogether and at once, or gradually and successively. And this 
motion (being always directed the same way with the generating force), 
if the body moved before, is added to or subducted from the former 
motion, according as they directly conspire with or are directly contrary 
to each other; or obliquely joined, when they are oblique, so as to pro- 
duce a new motion compounded from the determination of both. 

Law III. To every action there is always opposed an equal reaction; or 
the mutual actions of two bodies upon each other are always equal, and 
directed to contrary parts. 

Whatever draws or presses another is as much drawn or pressed by 
that other. If you press a stone with your finger, the finger is also pressed 
by the stone. If a horse draws a stone tied to a rope, the horse (if I may so 
say) will be equally drawn back towards the stone; for the distended rope, 
by the same endeavor to relax or unbend itself, will draw the horse 
as much towards the stone, as it does the stone towards the horse, and 
will obstruct the progress of the one as much as it advances that of the 
other. If a body impinge upon another, and by its force change the mo- 
tion of the other, that body also (because of the equality of the mutual 
pressure) will undergo an equal change, in its own motion, towards the 
contrary part. The changes made by these actions are equal, not in the 
velocities but in the motions of bodies; that is to say, if the bodies are 
not hindered by any other impediments. For, because the motions are 
equally changed, the changes of the velocities made towards contrary 
parts are reciprocally proportional to the bodies. 

From Newton's "Principia" edition of 7726 



In the year 1666 (at which time I applied myself to the grinding of 
optick glasses of other figures than spherical) I procured me a trian- 
gular glass prism, to try therewith the celebrated phaenomena of colours. 
And in order thereto, having darkened my chamber, and made a small 
hole in my window-shuts, to let in a convenient quantity of the sun's 
light, I placed my prism at its entrance, that it might be thereby re- 
fracted to the opposite wall. It was at first a very pleasing divertissement, 
to view the vivid and intense colours produced thereby; but after a while 
applying myself to consider them more circumspectly, I became surprised, 
to see them in an oblong form; which, according to the received laws 
of refraction, I expected should have been circular. They were terminated 
at the sides with straight lines, but at the ends, the decay of light was so 
gradual that it was difficult to determine justly, what was their figure; 
yet they seemed semicircular. 

Comparing the length of this coloured Spectrum with its breadth, I 
found it about five times greater, a disproportion so extravagant, that it 
excited me to a more than ordinary curiosity to examining from whence 
it might proceed. I could scarce think, that the various thicknesses of 
the glass, or the termination with shadow or darkness, could have any 
influence on light to produce such an effect; yet I thought it not amiss, 
first to examine those circumstances, and so try'd what would happen 
by transmitting light through parts of the glass of divers thicknesses, or 
through holes in the window of divers bignesses, or by setting the prism 
without, so that the light might pass through it, and be refracted, before 
it was terminated by the hole: But I found none of these circumstances 
material. The fashion of the colours was in all these cases the same. . . . 
The gradual removal of these suspicions led me to the Experimentum 
Crucis, which was this: I took two boards, and placed one of them close 
behind the prism at the window, so that the light might pass through a 
small hole, made in it for the purpose, and fall on the other board, which 
I placed at about 12 feet distance, having first made a small hole in it 
also, for some of the incident light to pass through. Then I placed an- 
other prism behind this second board, so that the light trajected through 
both the boards might pass through that also, and be again refracted be- 
fore it arrived at the wall. This done, I took the first prism in my hand, 
and turned it to and fro slowly about its axis, so much as to make the 
several parts of the image cast, on the second board, successively pass 
through the hole in it, that I might observe to what places on the wall 
the second prism would refract them. And I saw by the variation of those 


places, that the light, tending to that end of the image, towards which 
the refraction of the first prism was made, did in the second prism suffer a 
refraction considerably greater than the light tending to the other end. 
And so the true cause of the length of that image was detected to be no 
other, than that light is not similar or homogenial, but consists of 
Difform Rays, some of which are more Refrangible than others; so that 
without any difference in their incidence on the same medium, some shall 
be more Refracted than others; and therefore that, according to their 
particular Degrees of Refrangibility, they were transmitted through the 
prism to divers parts of the opposite wall. . . . 

On the Origin of Colours 

The colours of all natural bodies have no other origin than this, that 
they are variously qualified, to reflect one sort of light in greater plenty 
than another. And this I have experimented in a dark room, by illumi- 
nating those bodies with uncompounded light of divers colours. For by 
that means any body may be made to appear of any colour. They have 
there no appropriate colour, but ever appear of the colour of the light 
cast upon them, but yet with this difference, that they are most brisk 
and vivid in the light of their own daylight colour. Minium appeareth 
there of any colour indifferently, with which it is illustrated, but yet most 
luminous in red, and so bise appeareth indifferently of any colour, but 
yet most luminous in blue. And therefore minium reflecteth rays of any 
colour, but most copiously those endowed with red, that is, with all 
sorts of rays promiscuously blended, those qualified with red shall abound 
most in that reflected light, and by their prevalence cause it to appear 
of that colour. And for the same reason bise, reflecting blue most copiously, 
shall appear blue by the excess of those rays in its reflected light; and 
the like of other bodies. And that this is the entire and adequate cause 
of their colours, is manifest, because they have no power to change or 
alter the colours of any sort of rays incident apart, but put on all colours 
indifferently, with which they are enlightened. 

These things being so, it can be no longer disputed, whether there be 
colours in the dark, or whether they be the qualities of the objects we 
see, no nor perhaps, whether light be a body. For, since colours are the 
quality of light, having its rays for their entire and immediate subject, 
how can we think those rays qualities also, unless one quality may be the 
subject of, and sustain another; which in effect is to call it substance. 
We should not know bodies for substances; were it not for their sensible 
qualities, and the principle of those being now found due to something 
else, we have as good reason to believe that to be a substance also. 


Besides, who ever thought any quality to be a heterogeneous aggregate, 
such as light is discovered to be? But to determine more absolutely what 
light is, after what manner refracted, and by what modes or actions it 
produceth in our minds the phantasms of colours, is not so easie; and 
I shall not mingle conjectures with certainties. 

From Newton's "A New Theory about Light and Colours," 1672 

Mathematics, the Mirror of Civilization 


From Mathematics for the Million 


A Encyclopaedist and materialist, a foremost figure in the intellectual 
awakening which immediately preceded the French Revolution. Diderot 
was staying at the Russian court, where his elegant flippancy was enter- 
taining the nobility. Fearing that the faith of her retainers was at stake, 
the Tsaritsa commissioned Euler, the most distinguished mathematician 
of the time, to debate with Diderot in public. Diderot was informed that a 
mathematician had established a proof of the existence of God. He was 
summoned to court without being told the name of his opponent. Before 
the assembled court, Euler accosted him with the following pronounce- 

a + b n 

ment, which was uttered with due gravity: " = x, done Dieu 


existe repondez!" Algebra was Arabic to Diderot. Unfortunately he did 
not realize that was the trouble. Had he realized that algebra is just a 
language in which we describe the sizes of things in contrast to the 
ordinary languages which we use to describe the sorts of things in the 
world, he would have asked Euler to translate the first half of the sentence 
into French. Translated freely into English, it may be rendered: "A 
number x can be got by first adding a number a to a number b multiplied 
bv itself a certain number of times a and then dividing the whole by the 


number of 's multiplied together. So God exists after all. What have 
you got to say now?" If Diderot had asked Euler to illustrate the first 
part of his remark for the clearer understanding of the Russian court, 
Euler might have replied that x is 3 when a is i and b is 2 and n is 3, or 
that x is 21 when a is 3 and b is 3 and n is 4, and so forth. Euler's troubles 
would have begun when the court wanted to know how the second part 
of the sentence follows from the first part. Like many of us, Diderot had 
stagefright when confronted with a sentence in size language. He left 
the court abruptly amid the titters of the assembly, confined himself to 
his chambers, demanded a safe conduct, and promptly returned to France. 

Though he could not know it, Diderot had the last laugh before the 
court of history. The clericalism which Diderot fought was overthrown, 
and though it has never lacked the services of an eminent mathematician, 
the supernaturalism which Euler defended has been in retreat ever since. 
One eminent contemporary astronomer in his Gifford lectures tells us that 
Dirac has discovered p and q numbers. Done Dieu existe. Another distin- 
guished astronomer pauses, while he entertains us with astonishing calcu- 
lations about the distance of the stars, to award M. le grand Architects 
an honorary degree in mathematics. There were excellent precedents long 
before the times of Euler and Diderot. For the first mathematicians were 
the priestly calendar makers who calculated the onset of the seasons. The 
Egyptian temples were equipped with nilometers with which the priests 
made painstaking records of the rising and falling of the sacred river. 
With these they could predict the flooding of the Nile with great accuracy. 
Their papyri show that they possessed a language of measurement very 
different from the pretentious phraseology with which they fobbed off 
their prophecies on the laity. The masses could not see the connection 
between prophecy and reality, because the nilometers communicated with 
the river by underground channels, skilfully concealed from the eye of 
the people. The priests of Egypt used one language when they wrote in 
the proceedings of a learned society and another language when they gave 
an interview to the "sob sisters" of the Sunday press. 

In the ancient world writing and reading were still a mystery and 
a craft. The plain man could not decipher the Rhind papyrus in which 
the scribe Ahmes wrote down the laws of measuring things. Civilized 
societies in the twentieth century have democratized the reading and 
writing of sort language. Consequently the plain man can understand 
scientific discoveries if they do not involve complicated measurements. 
He knows something about evolution. The priestly accounts of the crea- 
tion have fallen into discredit. So mysticism has to take refuge in the 
atom. The atom is a safe place not because it is small, but because you 


have to do complicated measurements and use underground channels to 
find your way there. These underground channels are concealed from 
the eye of the people because the plain man has not been taught to read 
and write size language. Three centuries ago, when priests conducted 
their services in Latin, Protestant reformers founded grammar schools 
so that people could read the open bible. The time has now come for 
another Reformation. People must learn to read and write the language 
of measurement so that they can understand the open bible of modern 

In the time of Diderot the lives and happiness of individuals might still 
depend on holding the correct beliefs about religion. Today the lives and 
happiness of people depend more than most of us realize upon the correct 
interpretation of public statistics which are kept by Government offices. 
When a committee of experts announce that the average man can live 
on his unemployment allowance, or the average child is getting sufficient 
milk, the mere mention of an average or the citation of a list of figures 
is enough to paralyse intelligent criticism. In reality half or more than 
half the population may not be getting enough to live on when the 
average man or child has enough. The majority of people living today in 
civilized countries cannot read and write freely in size language, just as 
the majority of people living in the times of Wycliff and Luther were 
ignorant of Latin in which religious controversy was carried on. The 
modern Diderot has got to learn the language of size in self-defence, 
because no society is safe in the hands of its clever people. . . . 

The first men who dwelt in cities were talking animals. The man of 
the machine age is a calculating animal. We live in a welter of figures: 
cookery recipes, railway time-tables, unemployment aggregates, fines, 
taxes, war debts, overtime schedules, speed limits, bowling averages, 
betting odds, billiard scores, calories, babies' weights, clinical temperatures, 
rainfall, hours of sunshine, motoring records, power indices, gas-meter 
readings, bank rates, freight rates, death rates, discount, interest, lotteries, 
wave lengths, and tyre pressures. Every night, when he winds up his 
watch, the modern man adjusts a scientific instrument of a precision and 
delicacy unimaginable to the most cunning artificers of Alexandria in its 
prime. So much is commonplace. What escapes our notice is that in doing 
these things we have learnt to use devices which presented tremendous 
difficulties to the most brilliant mathematicians of antiquity. Ratios, limits, 
acceleration, are not remote abstractions, dimly apprehended by the 
solitary genius. They are photographed upon every page of our existence. 
We have no difficulty in answering questions which tortured the minds 
of very clever mathematicians in ancient times. This is not because you 


and I are very clever people. It is because we inherit a social culture which 
has suffered the impact of material forces foreign to the intellectual life 
of the ancient world. The most brilliant intellect is a prisoner within its 
own social inheritance. 

An illustration will help to make this quite definite at the outset. The 
Eleatic philosopher Zeno set all his contemporaries guessing by propound- 
ing a series of conundrums, of which the one most often quoted is the 
paradox of Achilles and the tortoise. Here is the problem about which 
the inventors of school geometry argued till they had speaker's throat and 
writer's cramp. Achilles runs a race with the tortoise. He runs ten times 
as fast as the tortoise. The tortoise has 100 yards' start. Now, says Zeno, 
Achilles runs 100 yards and reaches the place where the tortoise started. 
Meanwhile the tortoise has gone a tenth as far as Achilles, and is therefore 
10 yards ahead of Achilles. Achilles runs this 10 yards. Meanwhile the 
tortoise has run a tenth as far as Achilles, and is therefore i yard in front 
of him. Achilles runs this i yard. Meanwhile the tortoise has run a tenth 
of a yard and is therefore a tenth of a yard in front of Achilles. Achilles 
runs this tenth of a yard. Meanwhile the tortoise goes a tenth of a tenth 
of a yard. He is now a hundredth of a yard in front of Achilles. When 
Achilles has caught up this hundredth of a yard, the tortoise is a thou- 
sandth of a yard in front. So, argued Zeno, Achilles is always getting 
nearer the tortoise, but can never quite catch him up. 

You must not imagine that Zeno and all the wise men who argued the 
point failed to recognize that Achilles really did get past the tortoise. 
What troubled them was, where is the catch? You may have been asking 
the same question. The important point is that you did not ask it for the 
same reason which prompted them. What is worrying you is why they 
thought up funny little riddles of that sort. Indeed, what you are really 
concerned with is an historical problem. I am going to show you in a 
minute that the problem is not one which presents any mathematical 
difficulty to you. You know how to translate it into size language, because 
you inherit a social culture which is separated from theirs by the collapse 
of two great civilizations and by two great social revolutions. The 
difficulty of the ancients was not an historical difficulty. It was a mathe- 
matical difficulty. They had not evolved a size language into which this 
problem could be freely translated. 

The Greeks were not accustomed to speed limits and passenger-luggage 
allowances. They found any problem involving division very much more 
difficult than a problem involving multiplication. They had no way of 
doing division to any order of accuracy, because they relied for calculation 
on the mechanical aid of the counting frame or abacus. They could no^ 


do sums on paper. For all these and other reasons which we shall meet 
again and again, the Greek mathematician was unable to see something 
that we see without taking the trouble to worry about whether we see 
it or not. If we go on piling up bigger and bigger quantities, the pile goes 
on growing more rapidly without any end as long as we go on adding 
more. If we can go on adding larger and larger quantities indefinitely 
without coming to a stop, it seemed to Zeno's contemporaries that we 
ought to be able to go on adding smaller and still smaller quantities 
indefinitely without reaching a limit. They thought that in one case the 
pile goes on for ever, growing more rapidly, and in the other it goes on 
for ever, growing more slowly. There was nothing in their number 
language to suggest that when the engine slows beyond a certain point, 
it chokes off. 

To see this clearly we will first put down in numbers the distance which 
the tortoise traverses at different stages of the race after Achilles starts. 
As we have described it above, the tortoise moves 10 yards in stage i, 
i yard in stage 2, one-tenth of a yard in stage 3, one-hundredth of a yard 
in stage 4, etc. Suppose we had a number language like the Greeks and 
Romans, or the Hebrews, who used letters of the alphabet. Using the one 
that is familiar to us because it is still used for clocks, graveyards, and 
law-courts, we might write the total of all the distances the tortoise ran 
before Achilles caught him up like this: 

X + I + TT + -77 + 77 an d so on. 

We have put "and so on" because the ancient peoples got into great 
difficulties when they had to handle numbers more than a few thousands. 
Apart from the fact that we have left the tail of the series to your imagi- 
nation (and do not forget that the tail is most of the animal if it goes on 
for ever), notice another disadvantage about this script. There is absolutely 
nothing to suggest to you how the distances at each stage of the race are 
connected with one another. Today we have a number vocabulary which 
makes this relation perfectly evident, when we write it down as: 

i i i i i i 

10 + i H 1 1 1 1 1 and so on. 

10 100 1,000 10,000 100,000 1,000,000 

In this case we put "and so on" to save ourselves trouble, not because 
we have not the right number-words. These number-words were bor- 
rowed from the Hindus, who learnt to write number language after 
Zeno and Euclid had gone to their graves. A social revolution, the 


Protestant Reformation, gave us schools which made this number 
language the common property of mankind. A second social upheaval, 
the French Revolution, taught us to use a reformed spelling. Thanks 
to the Education Acts of the nineteenth century, this reformed spelling 
is part of the common fund of knowledge shared by almost every sane 
individual in the English-speaking world. Let us write the last total, 
using this reformed spelling, which we call decimal notation. That is to 

10 + i + o-i + o-oi + o-ooi + o-oooi + o-ooooi + ooooooi and so on. 

We have only to use the reformed spelling to remind ourselves that this 
can be put in a more snappy form : 

iriiiiii etc., 
or still better: 


We recognize the fraction o-i as a quantity that is less than -ny and more 
than -fa. If we have not forgotten the arithmetic we learned at school, we 
may even remember that o-i corresponds with the fraction %. This means 
that, the longer we make the sum, o-i + o-oi 4- o-ooi, etc., the nearer it 
gets to , and it never grows bigger than . The total of all the yards 
the tortoise moves till there is no distance between himself and Achilles 
makes up just ii yards, and no more. 

You will now begin to see what was meant by saying that the riddle 
presents no mathematical difficulty to you. You have a number language 
constructed so that it can take into account a possibility which mathema- 
ticians describe by a very impressive name. They call it the convergence 
of an infinite series to a limiting value. Put in plain words, this only 
means that, if you go on piling up smaller and smaller quantities as long 
as you can, you may get a pile of which the size is not made measurably 
larger by adding any more. The immense difficulty which the mathema- 
ticians of the ancient world experienced when they dealt with a process 
of division carried on indefinitely, or with what modern mathematicians 
call infinite series, limits, transcendental numbers, irrational quantities, 
and so forth, provides an example of a great social truth borne out by 
the whole history of human knowledge. Fruitful intellectual activity of 
the cleverest people draws its strength from the common knowledge 
which all of us share. Beyond a certain point clever people can never 
transcend the limitations of the social culture they inherit. When clever 
people pride themselves on their own isolation, we may well wonder 
whether they are very clever after all. Our studies in mathematics are 


going to show us that whenever the culture of a people loses contact 
with the common life of mankind and becomes exclusively the plaything 
of a leisure class, it is becoming a priestcraft. It is destined to end, as does 
all priestcraft, in superstition. To be proud of intellectual isolation from 
the common life of mankind and to be disdainful of the great social task 
of education is as stupid as it is wicked. It is the end of progress in knowl- 
edge. History shows that superstitions are not manufactured by the plain 
man. They are invented by neurotic intellectuals with too little to do. 
The mathematician and the plain man each need one another. Maybe the 
Western world is about to be plunged irrevocably into barbarism. If it 
escapes this fate, the men and women of the leisure state which is now 
within our grasp will regard the democratization of mathematics as a 
decisive step in the advance of civilization. 

In such a time as ours the danger of retreat into barbarism is very real. 
We may apply to mathematics the words in which Cobbett explained the 
uses of grammar to the working men of his own day when there was no 
public system of free schools. In the first of his letters on English gram- 
mar for a working boy, Cobbett wrote these words: "But, to the acquiring 
of this branch of knowledge, my dear son, there is one motive, which, 
though it ought, at all times, to be strongly felt, ought, at the present 
time, to be so felt in an extraordinary degree. I mean that desire which 
every man, and especially every young man, should entertain to be able 
to assert with effect the rights and liberties of his country. When you 
come to read the history of those Laws of England by which the freedom 
of the people has been secured . . . you will find that tyranny has no 
enemy so formidable as the pen. And, while you will see with exultation 
the long-imprisoned, the heavily-fined, the banished William Prynne, 
returning to liberty, borne by the people from Southampton to London, 
over a road strewed with flowers: then accusing, bringing to trial and to 
the block, the tyrants from whose hands he and his country had unjustly 
and cruelly suffered; while your heart and the heart of every young man 
in the kingdom will bound with joy at the spectacle, you ought all to bear 
in mind, that, without a knowledge of grammar, Mr. Prynne could 
never have performed any of those acts by which his name has been 
thus preserved, and which have caused his name to be held in honour." 

Today economic tyranny has no more powerful friend than the cal- 
culating prodigy. Without a knowledge of mathematics, the grammar 
of size and order, we cannot plan the rational society in which there will 
be leisure for all and poverty for none. If we are inclined to be a little 
afraid of the prospect, our first step towards understanding this grammar 
is to realize that the reasons which repel many people from studying 


it are not at all discreditable. As mathematics has been taught and 
expounded in schools no effort is made to show its social history, its 
significance in our own social lives, the immense dependence of civilized 
mankind upon it. Neither as children nor as adults are we told how the 
knowledge of this grammar has been used again and again throughout 
history to assist in the liberation of mankind from superstition. We are 
not shown how it may be used by us to defend the liberties of the people. 
Let us see why this is so. 

The educational system of North- Western Europe was largely moulded 
by three independent factors in the period of the Reformation. One was 
linguistic in the ordinary sense. To weaken the power of the Church as 
an economic overlord it was necessary to destroy the influence of the 
Church on the imagination of the people. The Protestant Reformers 
appealed to the recognized authority of scripture to show that the priestly 
practices were innovations. They had to make the scriptures an open book. 
The invention of printing was the mechanical instrument which destroyed 
the intellectual power of the Pope. Instruction in Latin and Greek was 
a corollary of the doctrine of the open bible. This prompted the great 
educational innovation of John Knox and abetted the more parsimonious 
founding of grammar schools in England. The ideological front against 
popery and the wealthy monasteries strengthened its strategic position by 
new translations and critical inspection of the scriptural texts. That is one 
reason why classical scholarship occupied a place of high honour in the 
educational system of the middle classes. 

The language of size owes its position in Western education to two dif- 
ferent social influences. While revolt against the authority of the Church 
was gathering force, and before the reformed doctrine had begun to have 
a wide appeal for the merchants and craftsmen of the medieval boroughs, 
the mercantile needs of the Hansa had already led to the founding of 
special schools in Germany for the teaching of the new arithmetic which 
Europe had borrowed from the Arabs. An astonishing proportion of the 
books printed in the three years after the first press was set up were com- 
mercial arithmetics. Luther vindicated the four merchant gospels of 
addition, subtraction, multiplication, and division with astute political 
sagacity when he announced the outlandish doctrine that every boy should 
be taught to calculate. The grammar of numbers was chained down to 
commercial uses before people could foresee the vast variety of ways in 
which it was about to invade man's social life. 

Geometry, already divorced from the art of calculation, did not enter 
into Western education by the same route. Apart from the stimulus which 
the study of dead languages received from the manufacture of bibles, 


classical pursuits were encouraged because the political theories of the 
Greek philosophers were congenial to the merchants who were aspiring to 
a limited urban democracy. The appeal of the city-state democracy to the 
imagination of the wealthier bourgeois lasted till after the French Revolu- 
tion, when it was laid to rest in the familiar funeral urns of mural decora- 
tion. The leisure class of the Greek city-states played with geometry as 
people play with crossword puzzles and chess today. Plato taught that 
geometry was the highest exercise to which human leisure could be 
devoted. So geometry became included in European education as a part of 
classical scholarship, without any clear connection with the contemporary 
reality of measuring Drake's "world encompassed." Those who taught 
Euclid did not understand its social use, and generations of schoolboys 
have studied Euclid without being told how a later geometry, which 
grew out of Euclid's teaching in the busy life of Alexandria, made it 
possible to measure the size of the world. Those measurements blew up 
the pagan Pantheon of star gods and blazed the trail for the great naviga- 
tions. The revelation of how much of the surface of our world was still 
unexplored was the solid ground for what we call the faith of Columbus. 
Plato's exaltation of mathematics as an august and mysterious ritual had 
its roots in dark superstitions which troubled, and fanciful puerilities 
which entranced, people who were living through the childhood of 
civilization, when even the cleverest people could not clearly distinguish 
the difference between saying that 13 is a "prime" number and saying 
that 13 is an unlucky number. His influence on education has spread a veil 
of mystery over mathematics and helped to preserve the queer freemasonry 
of the Pythagorean brotherhoods, whose members were put to death for 
revealing mathematical secrets now printed in school books. It reflects 
no discredit on anybody if this veil of mystery makes the subject distaste- 
ful. Plato's great achievement was to invent a religion which satisfies the 
emotional needs of people who are out of harmony with their social 
environment, and just too intelligent or too individualistic to seek 
sanctuary in the cruder forms of animism. The curiosity of the men who 
first speculated about atoms, studied the properties of the lodestone, 
watched the result of rubbing amber, dissected animals, and catalogued 
plants in the three centuries before Aristotle wrote his epitaph on Greek 
science, had banished personalities from natural and familiar objects. 
Plato placed animism beyond the reach of experimental exposure by 
inventing a world of "universals." This world of universals was the world 
as God knows it, the "real" world of which our own is but the shadow. 
In this "real" world symbols of speech and number are invested with the 


magic which departed from the bodies of beasts and the trunks of trees 
as soon as they were dissected and described. . . . 

Two views are commonly held about mathematics. One comes from 
Plato. This is that mathematical statements represent eternal truths. Plato's 
doctrine was used by the German philosopher, Kant, as a stick with which 
to beat the materialists of his time, when revolutionary writings like those 
of Diderot were challenging priestcraft. Kant thought that the principles 
of geometry were eternal, and that they were totally independent of our 
sense organs. It happened that Kant wrote just before biologists dis- 
covered that we have a sense organ, part of what is called the internal ear, 
sensitive to the pull of gravitation. Since that discovery, the significance 
of which was first fully recognized by the German physicist, Ernst Mach, 
the geometry which Kant knew has been brought down to earth by 
Einstein. It no longer dwells in the sky where Plato put it. We know 
that geometrical statements when applied to the real world are only 
approximate truths. The theory of Relativity has been very unsettling 
to mathematicians, and it has now become a fashion to say that mathemat- 
ics is only a game. Of course, this does not tell us anything about mathe- 
matics. It only tells us something about the cultural limitations of some 
mathematicians. When a man says that mathematics is a game, he is 
making a private statement. He is telling us something about himself, his 
own attitude to mathematics. He is not telling us anything about the 
public meaning of a mathematical statement, 

If mathematics is a game, there is no reason why people should play it 
if they do not want to. With football, it belongs to those amusements 
without which life would be endurable. The view which we explore is that 
mathematics is the language of size, and that it is an essential part of the 
equipment of an intelligent citizen to understand this language. If the 
rules of mathematics are rules of grammar, there is no stupidity involved 
when we fail to see that a mathematical truth is obvious. The rules of 
ordinary grammar are not obvious. They have to be learned. They are not 
eternal truths. They are conveniences without whose aid truths about 
the sorts of things in the world cannot be communicated from one person 
to another. In Cobbett's memorable words, Mr. Prynne would not have 
been able to impeach Archbishop Laud if his command of grammar 
had been insufficient to make himself understood. So it is with mathe- 
matics, the grammar of size. The rules of mathematics are rules to be 
learned. If they are formidable, they are formidable because they are 
unfamiliar when you first meet them like gerunds or nominative ab- 
solutes. They are also formidable because in all languages there are so 
many rules and words to memorize before we can read newspapers or 


pick up radio news from foreign stations. Everybody knows that being 
able to chatter in several foreign languages is not a sign of great social 
intelligence. Neither is being able to chatter in the language of size. Real 
social intelligence lies in the use of a language, in applying the right 
words in the right context. It is important to know the language of size, 
because entrusting the laws of human society, social statistics, population, 
man's hereditary make-up, the balance of trade, to the isolated mathema- 
tician without checking his conclusions is like letting a committee of 
philologists manufacture the truths of human, animal, or plant anatomy 
from the resources of their own imaginations. 

. . . The language of mathematics differs from that of everyday life, 
because it is essentially a rationally planned language. The languages 
of size have no place for private sentiment, either of the individual or 
of the nation. They are international languages like the binomial 
nomenclature of natural history. In dealing with the immense com- 
plexity of his social life man has not yet begun to apply inventiveness 
to the rational planning of ordinary language when describing different 
kinds of institutions and human behavior. The language of everyday 
life is clogged with sentiment, and the science of human nature has 
not advanced so far that we can describe individual sentiment in a 
clear way. So constructive thought about human society is hampered 
by the same conservatism as embarrassed the earlier naturalists. Nowa- 
days people do not differ about what sort of animal is meant by Cimex or 
Pediculus, because these words are only used by people who use them in 
one way. They still can and often do mean a lot of different things when 
they say that a mattress is infested with bugs or lice. The study of man's 
social life has not yet brought forth a Linnaeus. So an argument about 
the "withering away of the State" may disclose a difference about the 
use of the dictionary when no real difference about the use of the police- 
man is involved. Curiously enough, people who are most sensible about 
the need for planning other social amenities in a reasonable way are often 
slow to see the need for creating a rational and international language. 

The technique of measurement and counting has followed the caravans 
and galleys of the great trade routes. It has developed very slowly. At 
least four thousand years intervened between the time when men could 
calculate when the next eclipse would occur and the time when men could 
calculate how much iron is present in the sun. Between the first recorded 
observations of electricity produced by friction and the measurement of 
the attraction of an electrified body two thousand years intervened. Per- 
haps a longer period separates the knowledge of magnetic iron (or lode- 
stone) and the measurement of magnetic force. Classifying things accord- 


ing to size has been a much harder task than recognizing the different sorts 
of things there are. It has been more closely related to man's social achieve- 
ments than to his biological equipment. Our eyes and ears can recognize 
different sorts of things at a great distance. To measure things at a dis- 
tance, man has had to make new sense organs for himself, like the 
astrolabe, the telescope, and the microphone. He has made scales which 
reveal differences of weight to which our hands are quite insensitive. At 
each stage in the evolution of the tools of measurement man has refined 
the tools of size language. As human inventiveness has turned from the 
counting of flocks and seasons to the building of temples, from the build- 
ing of temples to the steering of ships into chartless seas, from seafaring 
plunder to machines driven by the forces of dead matter, new languages 
of size have sprung up in succession. Civilizations have risen and fallen. 
At each stage a more primitive, less sophisticated culture breaks through 
the barriers of custom thought, brings fresh rules to the grammar of 
measurement, bearing within itself the limitation of further growth and the 
inevitability that it will be superseded in its turn. The history of mathe- 
matics is the mirror of civilization. 

The beginnings of a size language are to be found in the priestly 
civilizations of Egypt and Sumeria. From these ancient civilizations we 
see the first-fruits of secular knowledge radiated along the inland trade 
routes to China and pushing out into and beyond the Mediterranean, 
where the Semitic peoples are sending forth ships to trade in tin and dyes. 
The more primitive northern invaders of Greece and Asia Minor collect 
and absorb the secrets of the pyramid makers in cities where a priestly 
caste is not yet established. As the Greeks become prosperous, geometry 
becomes a plaything. Greek thought itself becomes corrupted with the 
star worship of the ancient world. At the very point when it seems almost 
inevitable that geometry will make way for a new language, it ceases to 
develop further. The scene shifts to Alexandria, the greatest centre of ship- 
ping and the mechanical arts in the ancient world. Men are thinking about 
how much of the world remains to be explored. Geometry is applied to the 
measurement of the heavens. Trigonometry takes its place. The size of the 
earth, the distance of the sun and moon are measured. The star gods are 
degraded. In the intellectual life of Alexandria, the factory of world 
religions, the old syncretism has lost its credibility. It may still welcome 
a god beyond the sky. It is losing faith in the gods within the sky. 

In Alexandria, where the new language of star measurement has its 
beginnings, men are thinking about numbers unimaginably large 
compared with the numbers which the Greek intellect could grasp. 
Anaxagoras had shocked the court of Pericles by declaring that the sun 


was as immense as the mainland of Greece, Now Greece itself had sunk 
into insignificance beside the world of which Eratosthenes and Poseidonius 
had measured the circumference. The world itself sank into insignifi- 
cance beside the sun as Aristarchus had measured it. Ere the dark night of 
monkish superstition engulfed the great cosmopolis of antiquity, men were 
groping for new means of calculation. The bars of the counting frame had 
become the bars of a cage in which the intellectual life of Alexandria was 
imprisoned. Men like Diophantus and Theon were using geometrical 
diagrams to devise crude recipes for calculation. They had almost invented 
the third new language of algebra. That they did not succeed was the 
nemesis of the social culture they inherited. In the East the Hindus had 
started from a much lower level. Without the incubus of an old-established 
vocabulary of number, they had fashioned new symbols which lent them- 
selves to simple calculation without mechanical aids. The Moslem civiliza- 
tion which swept across the southern domain of the Roman Empire 
brought together the technique of measurement, as it had evolved in the 
hands of the Greeks and the Alexandrians, adding the new instrument 
for handling numbers which was developed through the invention of the 
Hindu number symbols. In the hands of Arabic mathematicians like Omar 
Khayyam, the main features of a language of calculation took shape. We 
still call it by the Arabic name, algebra. We owe algebra and the pattern 
of modern European poetry to a non-Aryan people who would be excluded 
from the vote in the Union of South Africa. 

Along the trade routes this new arithmetic is brought into Europe 
by Jewish scholars from the Moorish universities of Spain and by Gentile 
merchants trading with the Levant, some of them patronized by nobles 
whose outlook had been unintentionally broadened by the Crusades. 
Europe stands on the threshold of the great navigations. Seafarers are 
carrying Jewish astronomers who can use the star almanacs which Arab 
scholarship had prepared. The merchants are becoming rich. More than 
ever the world is thinking in large numbers. The new arithmetic or 
"algorithm" sponsors an amazing device which was prompted by the need 
for more accurate tables of star measurement for use in seafaring. Loga- 
rithms were among the cultural first-fruits of the great navigations. Mathe- 
maticians are thinking in maps, in latitude and longitude. A new kind 
of geometry (what we call graphs in everyday speech) was an inevitable 
consequence. This new geometry of Descartes contains something which 
Greek geometry had left out. In the leisurely world of antiquity there were 
no clocks. In the bustling world of the great navigations mechanical 
clocks are displacing the ancient ceremonial function of the priesthood as 
timekeepers. A geometry which could represent time and a religion in 


which there were no saints' days are emerging from the same social 
context. From this geometry of time a group of men who were studying 
the mechanics of the pendulum clock and making fresh discoveries about 
the motion of the planets devised a new size language to measure motion. 
Today we call it "the" calculus. 

This crude outline of the history of mathematics as a mirror of civiliza- 
tion, interlocking with man's common culture, his inventions, his economic 
arrangements, his religious beliefs, may be left at the stage which had been 
reached when Newton died. What has happened since has been largely 
the filling of gaps, the sharpening of instruments already devised. Here 
and there are indications of a new sort of mathematics. We see a hint of 
it in social statistics and the study of the atom. We begin to see possi- 
bilities of new languages of size transcending those we now use, as the 
calculus of movement gathered into itself all that had gone before. 


Experiments and Ideas 



As frequent mention is made in public papers from Europe of the 
success of the Philadelphia experiment for drawing the electric fire from 
clouds by means of pointed rods of iron erected on high buildings, &, it 
may be agreeable to the curious to be informed, that the same experi- 
ment has succeeded in Philadelphia, though made in a different and 
more easy manner, which is as follows: 

Make a small cross of two light strips of cedar, the arms so long as to 
reach to the four corners of a large thin silk handkerchief when extended; 
tie the corners of the handkerchief to the extremities of the cross, so you 
have the body of a kite; which being properly accommodated with a 
tail, loop, and string, will rise in the air, like those made of paper; but 
this being of silk, is fitter to bear the wet and wind of a thunder-gust 
without tearing. To the top of the upright stick of the cross is to be fixed 
a very sharp pointed wire, rising a foot or more above the wood. To 
the end of the twine, next the hand, is to be tied a silk ribbon, and where 
the silk and twine join, a key may be fastened. This kite is to be raised 
when a thunder-gust appears to be coming on, and the person who holds 
the string must stand within a door or window or under some cover, 
so that the silk ribbon may not be wet; and care must be taken that the 
twine does not touch the frame of the door or window. As soon as any of 
the thunder-clouds come over the kite, the pointed wire will draw the 
electric fire from them, and the kite, with all the twine, will be electrified, 
and the loose filaments of the twine will stand out every way, and be 
attracted by an approaching finger. And when the rain has wet the kite 
and twine, so that it can conduct the electric fire freely, you will find it 
stream out plentifully from the key on the approach of your knuckle. 
At this key the phial may charged; and from electric fire thus obtained, 
spirits may be kindled, and all the other electric experiments be per- 



formed, which are usually done by the help of a rubbed glass globe or 
tube, and thereby the sameness of the electric matter with that of lightning 
completely demonstrated. Letter to Peter Collinson, 1752 


Your question, how I came first to think of proposing the experiment 
of drawing down the lightning, in order to ascertain its sameness with 
the electric fluid, I cannot answer better than by giving you an extract 
from the minutes I used to keep of the experiments I made, with 
memorandums of such as I purposed to make, the reasons for making 
them, and the observations that arose upon them, from which minutes my 
letters were afterwards drawn. By this extract you will see, that the 
thought was not so much "an out-of-the-way one," but that it might 
have occurred to any electrician. 

"November 7, 1749. Electrical fluid agrees with lightning in these par- 
ticulars, i. Giving light. 2. Colour of the light. 3. Crooked direction. 
4. Swift motion. 5. Being conducted by metals. 6. Crack or noise in explod- 
ing. 7. Subsisting in water or ice. 8. Rending bodies it passes through. 
9. Destroying animals. 10. Melting metals, n. Firing inflammable sub- 
stances. 12. Sulphureous smell. The electric fluid is attracted by points. 
We do not know whether this property is in lightning. But since they 
agree in all particulars wherein we can already compare them, is it not 
probable they agree likewise in this ? Let the experiment be made." . . 

The knocking down of the six men was performed with two of my 
large jarrs not fully charged. I laid one end of my discharging rod upon 
the head of the first; he laid his hand on the head of the second; the 
second his hand on the head of the third, and so to the last, who held, 
in his hand, the chain that was connected with the outside of the jarrs. 
When they were thus placed, I applied the other end of my rod to the 
prime-conductor, and they all dropt together. When they got up, they all 
declared they had not felt any stroke, and wondered how they came to 
fall; nor did any of them either hear the crack, or see the light of it. 
You suppose it a dangerous experiment; but I had once suffered the same 
myself, receiving, by accident, an equal stroke through my head, that 
struck me down, without hurting me: And I had seen a young woman, 
that was about to be electrified through the feet, (for some indisposition) 
receive a greater charge through the head, by inadvertently stooping for- 
ward to look at the placing of her feet, till her forhead (as she was very 
tall) came too near my prime-conductor: she dropt, but instantly got up 


again, complaining o nothing. A person so struck, sinks down doubled, 
or folded together as it were, the joints losing their strength and stiffness 
at once, so that he drops on the spot where he stood, instantly, and there 
is no previous staggering, nor does he ever fall lengthwise. Too great a 
charge might, indeed, kill a man, but I have not yet seen any hurt done 
by it. It would certainly, as you observe, be the easiest of all deaths. . . - 

Letter to John Lining, 7755 


Agreeable to your request, I send you my reasons for thinking that our 
northeast storms in North America begin first, in point of time, in the 
southwest parts: That is to say, the air in Georgia, the farthest of our 
colonies to the Southwest, begins to move southwesterly before the air 
of Carolina, which is the next colony northeastward; the air of Carolina 
has the same motion before the air of Virginia, which lies still more 
northeastward; and so on northeasterly through Pennsylvania, New-York, 
New-England, &c., quite to Newfoundland. 

These northeast storms are generally very violent, continue sometimes 
two or three days, and often do considerable damage in the harbours 
along the coast. They are attended with thick clouds and rain. 

What first gave me this idea, was the following circumstance. About 
twenty years ago, a few more or less, I cannot from my memory be cer- 
tain, we were to have an eclipse of the moon at Philadelphia, on a Fri- 
day evening, about nine o'clock. I intended to observe it, but was pre- 
vented by a northeast storm, which came on about seven, with thick 
clouds as usual, that quite obscured the whole hemisphere. Yet when the 
post brought us the Boston newspaper, giving an account of the effects 
of the same storm in those parts, I found the beginning of the eclipse 
had been well observed there, though Boston lies N. E. of Philadelphia 
about 400 miles. This puzzled me because the storm began with us so 
soon as to prevent any observation, and being a N. E. storm, I imagined 
it must have begun rather sooner in places farther to the northeastward 
than it did at Philadelphia. I therefore mentioned it in a letter to my 
brother, who lived at Boston; and he informed me the storm did not 
begin with them till near eleven o'clock, so that they had a good observa- 
tion of the eclipse: And upon comparing all the other accounts I received 
from the several colonies, of the time of beginning of the same storm, and, 
since that of other storms of the same kind, 1^ found the beginning to 
be always later the farther northeastward. I have not my notes with me 


here in England, and cannot, from memory, say the proportion o time 
to distance, but I think it is about an hour to every hundred miles. 

From thence I formed an idea of the cause of these storms, which I 
would explain by a familiar instance or two. Suppose a long canal of 
water stopp'd at the end by a gate. The water is quite at rest till the 
gate is open, then it begins to move out through the gate; the water next 
the gate is first in motion, and moves towards the gate; the water next 
to that first water moves next, and so on successively, till the water at 
the head of the canal is in motion, which is last of all. In this case all the 
water moves indeed towards the gate, but the successive times of begin- 
ning motion are the contrary way, viz. from the gate backwards to the 
head of the canal. Again, suppose the air in a chamber at rest, no cur- 
rent through the room till you make a fire in the chimney. Immediately 
the air in the chimney, being rarefied by the fire, rises; the air next the 
chimney flows in to supply its place, moving towards the chimney; and, 
in consequence, the rest of the air successively, quite back to the door. 
Thus to produce our northeast storms, I suppose some great heat and 
rarefaction of the air in or about the Gulph of Mexico; the air thence 
rising has its place supplied by the next more northern, cooler, and there- 
fore denser and heavier, air; that, being in motion, is followed by the 
next more northern air, &c. &c., in a successive current, to which current 
our coast and inland ridge of mountains give the direction of northeast, 
as they lie N.E. and S.W. Letter to Alexander Small, 1760 


I have this day received your favor of the 2d inst. Every information 
in my power, respecting the balloons, I sent you just before Christmas, 
contained in copies of my letters to Sir Joseph Banks. There is no secret 
in the affair, and I make no doubt that a person coming from you would 
easily obtain a sight of the different balloons of Montgolfier and Charles, 
with all the instructions wanted; and, if you undertake to make one, 
I think it extremely proper and necessary to send an ingenious man here 
for that purpose; otherwise, for want of attention to some particular cir- 
cumstance, or of not being acquainted with it, the experiment might mis- 
carry, which, in an affair of so much public expectation, would have 
bad consequences, draw upon you a great deal of censure, and affect your 
reputation. It is a serious thing to draw out from their affairs all the 
inhabitants of a great city and its environs, and a disappointment makes 
them angry. At Bourdeaux lately a person who pretended to send up a 
balloon, and had received money from many people, not being able to 


make it rise, the populace were so exasperated that they pulled down his 
house and had like to have killed him. 

It appears, as you observe, to be a discovery of great importance, and 
what may possibly give a new turn to human affairs. Convincing 
sovereigns of the folly of wars may perhaps be one effect of it; since it will 
be impracticable for the most potent of them to guard his dominions. 
Five thousand balloons, capable of raising two men each, could not cost 
more than five ships of the line; and where is the prince who can afford 
so to cover his country with troops for its defence, as that ten thousand 
men descending from the clouds might not in many places do an infi- 
nite deal of mischief, before a force could be brought together to repel 
them? , . . Letter to Jan Ingcnhousz, 1784 


You often entertain us with accounts of new discoveries. Permit me to 
communicate to the public, through your paper, one that has lately been 
made by myself, and which I conceive may be of great utility. 

I was the other evening in a grand company, where the new lamp of 
Messrs. Quinquet and Lange was introduced, and much admired for its 
splendour; but a general inquiry was made, whether the oil it consumed 
was not in proportion to the light it afforded, in which case there would 
be no saving in the use of it. No one present could satisfy us in that 
point, which all agreed ought to be known, it being a very desirable 
thing to lessen, if possible, the expense of lighting our apartments, when 
every other article of family expense was so much augmented. 

I was pleased to see this general concern for economy, for I love economy 

I went home, and to bed, three or four hours after midnight, with my 
head full of the subject. An accidental sudden noise waked me about six 
in the morning, when I was surprised to find my room filled with light; 
and I imagined at first, that a number of those lamps had been brought 
into it; but, rubbing my eyes, I perceived the light came in at the win- 
dows. I got up and looked out to see what might be the occasion of it, 
when I saw the sun just rising above the horizon, from where he poured 
his rays plentifully into my chamber, my domestic having negligently 
omitted, the preceding evening, to close the shutters. 

I looked at my watch, which goes very well, and found that it was but 
six o'clock; and still thinking it something extraordinary that the sun 
should rise so early, I looked into the almanac, where I found it to be the 
hour given for his rising on that day. I looked forward, too, and found he 


was to rise still earlier every day till towards the end of June; and that 
at no time in the year he retarded his rising so long as till eight o'clock. 
Your readers, who with me have never seen any signs of sunshine before 
noon, and seldom regard the astronomical part of the almanac, will be as 
much astonished as I was, when they hear of his rising so early; and 
especially when I assure them, that he gives light as soon as he rises. I 
am convinced of this. I am certain of my fact. One cannot be more 
certain of any fact. I saw it with my own eyes. And, having repeated 
this observation the three following mornings, I found always precisely 
the same result. . . . 

This event has given rise in my mind to several serious and important 
reflections. I considered that, if I had not been awakened so early in the 
morning, I should have slept six hours longer by the light of the sun, 
and in exchange have lived six hours the following night by candle- 
light; and, the latter being a much more expensive light than the former, 
my love of economy induced me to muster up what little arithmetic I was 
master of, and to make some calculations, which I shall give you, after 
observing that utility is, in my opinion the test of value in matters of 
invention, and that a discovery which can be applied to no use, or is not 
good for something, is good for nothing. 

I took for the basis of my calculation the supposition that there are one 
hundred thousand families in Paris, and that these families consume in 
the night half a pound of bougies, or candles, per hour. I think this is a 
moderate allowance, taking one family with another; for though, I believe 
some consume less, I know that many consume a great deal more. Then 
estimating seven hours per day as the medium quantity between the 
time of the sun's rising and ours, he rising during the six following 
months from six to eight hours before noon, and there being seven hours 
of course per night in which we burn candles, the account will stand 

In the six months between the 20th of March and the 2oth of September, 
there are 

Nights 183 

Hours of each night in which we burn candles 7 

Multiplication gives for the total number of hours 1,281 

These 1,281 hours multiplied by 100,000, the number of 

inhabitants, give 128,100,000 

One hundred twenty-eight millions and one hundred thousand 
hours, spent at Paris by candle-light, which, at half a pound 
of wax and tallow per hour, gives the weight of 64,050,000 


Sixty-four millions and fifty thousand of pounds, which, esti- 
mating the whole at the medium price of thirty sols the 
pound, makes the sum of ninety-six millions and seventy- 
five thousand livres tournois 96,075,000 

An immense sum! that the city of Paris might save every year, by the 
economy of using sunshine instead of candles. . . . 

Letter to the Authors of "The Journal of Paris," 1784 


By Mr. Dollond's saying, that my double spectacles can only serve par- 
ticular eyes, I doubt he has not been rightly informed of their construc- 
tion. I imagine it will be found pretty generally true, that the same 
convexity of glass, through which a man sees clearest and best at the 
distance proper for reading, is not the best for greater distances. I there- 
fore had formerly two pair of spectacles, which I shifted occasionally, as 
in travelling I sometimes read, and often wanted to regard the prospects. 
Finding this change troublesome, and not always sufficiently ready, I had 
the glasses cut, and half of each kind associated in the same circle. . . . 

By this means, as I wear my spectacles constantly, I have only to move 
my eyes up or down, as I want to see distinctly far or near, the proper 
glasses being always ready. This I find more particularly convenient since 
my being in France, the glasses that serve me best at table to see what 
I eat, not being the best to see the faces of those on the other side of the 
table who speak to me; and when one's ears are not well accustomed to 
the sounds of a language, a sight of the movements in the features of him 
that speaks helps to explain; so that I understand French better by the 
help of my spectacles. Letter to George Whatley, 1785 

Exploring the Atom 


From The Universe Around Us 

-* Greek philosophy was greatly exercised by the question of whether 
in the last resort the ultimate substance of the universe was continuous or 
discontinuous. We stand on the sea-shore, and all around us see stretches 
of sand which appear at first to be continuous in structure, but which a 
closer examination shews to consist of separate hard particles or grains. 
In front rolls the ocean, which also appears at first to be continuous in 
structure, and this we find we cannot divide into grains or particles, no 
matter how we try. We can divide it into drops, but then each drop can 
be subdivided into smaller drops, and there seems to be no reason, on the 
face of things, why this process of subdivision should not be continued 
for ever. The question which agitated the Greek philosophers was, in 
effect, whether the water of the ocean or the sand of the sea-shore gave 
the truest picture of the ultimate structure of the substance of the universe. 

The "atomic" school, founded by Dernocritus, Leucippus and Lucretius, 
believed in the ultimate discontinuity of matter; they taught that any 
substance, after it had been subdivided a sufficient number of times, would 
be found to consist of hard discrete particles which did not admit of 
further subdivision. For them the sand gave a better picture of ultimate 
structure than the water, because they thought that sufficient subdivision 
would cause the water to display the granular properties of sand. And this 
intuitional conjecture is amply confirmed by modern science. 

The question is, in effect, settled as soon as a thin layer of a substance 
is found to shew qualities essentially different from those of a slightly 
thicker layer. A layer of yellow sand swept uniformly over a red floor 
will make the whole floor appear yellow if there is enough sand to make 
a layer at least one grain thick. If, however, there is only half this much 
sand, the redness of the floor inevitably shews through; it is impossible 
to spread sand in a uniform layer only half a grain thick. This abrupt 



change in the properties of a layer o sand is of course a consequence of 
the granular structure of sand. 

Similar changes are found to occur in the properties of thin layers of 
liquid. A teaspoonful of soup will cover the bottom of a soup plate, but a 
single drop of soup will only make an untidy splash. In some cases it is 
possible to measure the exact thickness of layer at which the properties 
of liquids begin to change. In 1890 Lord Rayleigh found that thin films 
of olive oil floating on water changed their properties entirely as soon as 
the thickness of the film was reduced to below a millionth of a millimetre 
(or a 25,ooo,oooth part of an inch). The obvious interpretation, which is 
confirmed in innumerable ways, is that olive oil consists of discrete 
particles analogous to the "grains" in a pile of sand each having a 
diameter somewhere in the neighbourhood of a 25,ooo,oooth part of an 

Every substance consists of such "grains"; they are called molecules. 
The familiar properties of matter are those of layers many molecules 
thick; the properties of layers less than a single molecule thick are known 
only to the physicist in his laboratory. 


How are we to break up a piece of substance into its ultimate grains, 
or molecules? It is easy for the scientist to say that, by subdividing water 
for long enough, we shall come to grains which cannot be subdivided any 
further; the plain man would like to see it done. 

Fortunately the process is one of extreme simplicity. Take a glass of 
water, apply gentle heat underneath, and the water begins to evaporate. 
What does this mean? It means that the water is being broken up into 
its separate ultimate grains or molecules. If the glass of water could be 
placed on a sufficiently sensitive spring balance, we should see that the 
process of evaporation does not proceed continuously, layer after layer, 
but jerkily, moleciile by molecule. We should find the weight of the 
water changing by jumps, each jump representing the weight of a single 
molecule. The glass may contain any integral number of molecules but 
never fractional numbers if fractions of a molecule exist, at any rate 
they do not come into play in the evaporation of a glass of water. 

THE GASEOUS STATE. The molecules which break loose from the surface 
of the water as it evaporates form a gas water-vapour or steam. A gas 
consists of a vast number of molecules which fly about entirely independ- 
ently of one another, except at the rare instants at which two collide, 
and so interfere with each other's motion. The extent to which the mole- 
cules interfere with one another must obviously depend on their sizes; 


the larger they are, the more frequent their collisions will be, and the 
more they will interfere with one another's motion. Actually the extent 
of this interference provides the best means of estimating the sizes of 
molecules. They prove to be exceedingly small, being for the most part 
about a hundred-millionth of an inch in diameter, and, as a general rule, 
the simpler molecules have the smaller diameters, as we might perhaps 
have anticipated. The molecule of water has a diameter of 1.8 hundred- 
millionths of an inch (4.6 X io~ 8 cm.), while that of the simpler hydro- 
gen molecule is only just over a hundred-millionth of an inch (2.7 X 
io" 8 cm.). The fact that a number of different lines of investigation all 
assign the same diameters to these molecules provides an excellent proof 
of the reality of their existence. 

As molecules are so exceedingly small, they must also be exceedingly 
numerous. A pint of water contains 1.89 X io 25 molecules, each weighing 
i. 06 X io~ 24 ounce. If these molecules were placed end to end, they 
would form a chain capable of encircling the earth over 200 million times. 
If they were scattered over the whole land surface of the earth, there 
would be nearly 100 million molecules to every square inch of land. If 
we think of the molecules as tiny seeds, the total amount of seed needed 
to sow the whole earth at the rate of 100 million molecules to the square 
inch could be put into a pint pot. 

These molecules move with very high speeds; the molecules which 
constitute the ordinary air of an ordinary room move with an average 
speed of about 500 yards a second. This is roughly the speed of a rifle- 
bullet, and is rather more than the ordinary speed of sound. As we are 
familiar with this latter speed from everyday experience, it is easy to form 
some conception of molecular speeds in a gas. It is not a mere accident 
that molecular speeds are comparable with the speed of sound. Sound 
is a disturbance which one molecule passes on to another when it collides 
with it, rather like relays of messengers passing a message on to one 
another, or Greek torch-bearers handing on their lights. Between collisions 
the message is carried forward at exactly the speed at which the molecules 
travel. If these all travelled with precisely the same speed and in precisely 
the same direction, the sound would of course travel with just the speed 
of the molecules. But many of them travel on oblique courses, so that 
although the average speed of individual molecules in ordinary air is 
about 500 yards a second, the net forward velocity of the sound is only 
about 370 yards a second. 

At high temperatures the molecules may have even greater speeds; the 
molecules of steam in a boiler may move at 1000 yards a second. 

It is the high speed of molecular motion that is responsible for the 


great pressure exerted by a gas; any surface in contact with ordinary air 
is exposed to a hail of molecules each moving with the speed of a rifle- 
bullet. With each breath we take, swarms of millions of millions of 
millions of molecules enter our bodies, each moving at about 500 yards a 
second, and nothing but their incessant hammering on the walls of our 
lungs keeps our chests from collapsing. To take another instance, the 
piston in a locomotive cylinder is bombarded by about 14 X io 28 mole- 
cules every second, each moving at about 800 yards a second. This inces- 
sant fusillade of innumerable tiny bullets urges the piston forward in the 
cylinder, and so propels the train. . . . 


In the gaseous state, each separate molecule retains all the chemical 
properties of the solid or liquid substance from which it originated; 
molecules of steam, for instance, moisten salt or sugar, or combine with 
thirsty substances such as unslaked lime or potassium chloride, just as 
water does. 

Is it possible to break up the molecules still further? Lucretius and his 
predecessors would, of course, have said: "No." A simple experiment, 
which, however, was quite beyond their range, will speedily shew that 
they were wrong. 

On sliding the two wires of an ordinary electric bell circuit into a 
tumbler of water, down opposite sides, bubbles of gas will be found to 
collect on the wires, and chemical examination shews that the two lots of 
gas have entirely different properties. They cannot, then, both be water- 
vapour, and in point of fact neither of them is; one proves to be hydrogen 
and the other oxygen. There is found to be twice as much hydrogen as 
oxygen, whence we conclude that the electric current has broken up each 
molecule of water into two parts of hydrogen and one of oxygen. These 
smaller units into which a molecule is broken are called "atoms." Each 
molecule of water consists of two atoms of hydrogen (H) and one atom 
of oxygen (O) ; this is expressed in its chemical formula HbO. 

All the innumerable substances which occur on earth shoes, ships, 
sealing-wax, cabbages, kings, carpenters, walruses, oysters, everything we 
can think of can be analysed into their constituent atoms, either in this 
or in other ways. It might be thought that a quite incredible number of 
different kinds of atoms would emerge from the rich variety of sub- 
stances we find on earth. Actually the number is quite small. The same 
atoms turn up again and again, and the great variety of substances we 
find on earth results, not from any great variety of atoms entering into 
their composition, but from the great variety of ways in which a few 


types of atoms can be combined just as in a colour-print three colours 
can be combined so as to form almost all the colours we meet in nature, 
not to mention other weird hues such as never were on land or sea. 

Analysis of all known terrestrial substances has, so far, revealed only 
90 different kinds of atoms. Probably 92 exist, there being reasons for 
thinking that two, or possibly even more, still remain to be discovered. 
Even of the 90 already known, the majority are exceedingly rare, most 
common substances being formed out of the combinations of about 14 
different atoms, say hydrogen (H), carbon (C), nitrogen (N), oxygen 
(O), sodium (Na), magnesium (Mg), aluminum (Al), silicon (Si), 
phosphorus (P), sulphur (S), chlorine (Cl), potassium (K), calcium 
(Ca), and iron (Fe). 

In this way, the whole earth, with its endless diversity of substances, is 
found to be a building built of standard bricks the atoms. And of these 
only a few types, about 14, occur at all abundantly in the structure, the 
others appearing but rarely. 

SPECTROSCOPY. Just as a bell struck with a hammer emits a char- 
acteristic note, so every atom put in a flame or in an electric arc or discharge- 
tube, emits a characteristic light, which the spectroscope will resolve into 
its separate constituents. 

The spectrum of sunlight discloses the chemical composition of the 
solar atmosphere, and here again we still find the same types of atoms 
as on earth, and no others. With a few quite unimportant exceptions, 
every line in the sun's spectrum can be identified as originating from 
some type of atom already known on earth. Of the fifteen metals which 
are believed to be commonest in the sun's atmosphere, seven, which 
account for no less than 96 per cent, of the whole, figure in our list of the 
fourteen elements which are commonest on earth. Actually they are 
precisely the seven principal constituents of terrestrial rocks, although 
their relative proportions are different on the sun and earth. 

Thus, broadly speaking the same atoms occur in the sun's atmosphere 
as on earth, and the same is true of the atmospheres of the stars. It is 
tempting to jump to the generalisation that the whole universe is built 
solely of the 90 or 92 types of atoms found on earth, but at present there 
is no justification for this. The light we receive from the sun and stars 
comes only from the outermost layers of their surfaces, and so conveys no 
information at all as to the types of atoms to be found in the stars' 
interiors. Indeed we have no knowledge of the types of atoms which 
occur in the interior of our own earth. 

THE STRUCTURE OF THE ATOM. Until quite recently, atoms were 
regarded as the permanent bricks of which the whole universe was built. 


All the changes of the universe were supposed to amount to nothing 
more drastic than a re-arrangement of permanent indestructible atoms; 
like a child's box of bricks, these built many buildings in turn. The story 
of twentieth-century physics is primarily the story of the shattering of 
this concept. 

It was towards the end of the last century that Crookes, Lenard, and 
above all, Sir J. J. Thomson first began to break up the atom. The struc- 
tures which had been deemed the unbreakable bricks of the universe for 
more than 2000 years, were suddenly shown to be very susceptible to 
having fragments chipped off. A mile-stone was reached in 1897, when 
Thomson shewed that these fragments were identical no matter what 
type of atom they came from; they were of equal weight and they carried 
equal charges of negative electricity. On account of this last property they 
were called "electrons." The atom cannot, however, be built up of elec- 
trons and nothing else, for as each electron carries a negative charge of 
electricity, a structure which consisted of nothing but electrons would also 
carry a negative charge. Two negative charges of electricity repel one 
another, as also do two positive charges, while two charges, one of positive 
and one of negative electricity, attract one another. This makes it easy 
to determine whether any body or structure carries a positive or a negative 
charge of electricity, or no charge at all. Observation shews that a com- 
plete atom carries no charge at all, so that somewhere in the atom there 
must be a positive charge of electricity, of amount just sufficient to 
neutralise the combined negative charges of all the electrons. 

In 1911 experiments by Sir Ernest Rutherford and others revealed the 
architecture of the atom, in its main lines at least. As we shall soon see, 
nature herself provides an endless supply of small particles charged with 
positive electricity, and moving with very high speeds, in the a-particles 
shot off from radio-active substances. Rutherford's method was in brief 
to fire these into atoms and observe the result. And the surprising result 
he obtained was that the vast majority of these bullets passed straight 
through the atom as though it simply did not exist. It was like shooting 
at a ghost. 

Yet the atom was not all ghostly. A tiny fraction perhaps one in 
10,000 of the bullets were deflected from their courses as if they had met 
something very substantial indeed. A mathematical calculation shewed 
that these obstacles could only be the missing positive charges of the 

A detailed study of the paths of these projectiles proved that the whole 
positive charge of an atom must be concentrated in a single very small 
space, having dimensions of the order of only a millionth of a millionth of 


an inch. In this way, Rutherford was led to propound the view of atomic 
structure which is generally associated with his name. He supposed the 
chemical properties and nature of the atom to reside in a weighty, but 
excessively minute, central "nucleus" carrying a positive charge of elec- 
tricity, around which a number of negatively charged electrons described 
orbits. He had to suppose that the electrons were in motion in the atom, 
otherwise the attraction of positive for negative electricity would immedi- 
ately draw them into the central nucleus just as gravitational attraction 
would cause the earth to fall into the sun, were it not for the earth's 
orbital motion. In brief, Rutherford supposed the atom to be constructed 
like the solar system, the heavy central nucleus playing the part of the 
sun and the electrons acting the parts of the planets. 

The modern theory of wave-mechanics casts doubt on some at least 
of these concepts perhaps on all, although this is still in doubt. Thus it 
may prove necessary ro discard many or all of them before long. Yet 
Rutherford's concepts provide a simple and easily visualised picture of 
the atom, whereas the theory of wave-mechanics has not yet been able 
to provide a picture at all. For this reason we shall continue to describe 
the atom in terms of Rutherford's picture. 

According to this picture, the electrons are supposed to move round 
the nucleus with just the speeds necessary to save them from being 
drawn into it, and these speeds prove to be terrific, the average electron 
revolving around its nucleus several thousand million million times every 
second, with a speed of hundreds of miles a second. Thus the smallness 
of their orbits does not prevent the electrons moving with higher orbital 
speeds than the planets, or even the stars themselves. 

By clearing a space around the central nucleus, and so preventing other 
atoms from coming too near to it, these electronic orbits give size to the 
atom. The volume of space kept clear by the electrons is enormously 
greater than the total volume of the electrons; roughly, the ratio of 
volumes is that of the battlefield to the bullets. The atom has about 
100,000 times the diameter, and so about a thousand million million times 
the volume, of a single electron. The nucleus, although it generally weighs 
3000 or 4000 times as much as all the electrons in the atom together, is at 
most comparable in size with, and may be even smaller than, a single 

We know the extreme emptiness of astronomical space. Choose a point 
in space at random, and the odds against its being occupied by a star are 
enormous. Even the solar system consists overwhelmingly of empty space; 
choose a spot inside the solar system at random, and there are still 
immense odds against its being occupied by a planet or even by a comet, 


meteorite or smaller body. And now we see that this emptiness extends 
also to the space of physics. Even inside the atom we choose a point at 
random, and the odds against there being anything there are immense; 
they are of the order of at least millions of millions to one. Six specks 
of dust inside Waterloo Station represent or rather over-represent the 
extent to which space is crowded with stars. In the same way a few 
wasps six for the atom of carbon flying around in Waterloo Station 
will represent the extent to which the atom is crowded with electrons 
all the rest is emptiness. As we pass the whole structure of the universe 
under review, from the giant nebulae and the vast interstellar and inter- 
nebular spaces down to the tiny structure of the atom, little but vacant 
space passes before our mental gaze. We live in a gossamer universe; 
pattern, plan and design are there in abundance, but solid substance is 

ATOMIC NUMBERS. The number of elecrons which fly round in orbits 
in an atom is called the "atomic number" of the atom. Atoms of all 
atomic numbers from i to 92 have been found, except for two missing 
numbers 85 and 87. As already mentioned, it is highly probable that these 
also exist, and that there are 92 "elements" whose atomic numbers occupy 
the whole range of atomic numbers from i to 92 continuously. 

The atom of atomic number unity is of course the simplest of all. It is 
the hydrogen atom, in which a solitary electron revolves around a nucleus 
whose charge of positive electricity is exactly equal in amount, although 
opposite in sign, to the charge on the negative electron. 

Next comes the helium atom of atomic number 2, in which two elec- 
trons revolve about a nucleus which has four times the weight of the 
hydrogen nucleus although carrying only twice its electric charge. After 
this comes the lithium atom of atomic number 3, in which three electrons 
revolve around a nucleus having six times the weight of the hydrogen 
atom and three times its charge. And so it goes on, until we reach ura- 
nium, the heaviest of all atoms known on earth, which has 92 electrons 
describing orbits about a nucleus of 238 times the weight of the hydrogen 


While physical science was still engaged in breaking up the atom into 
its component factors, it made the further discovery that the nuclei them- 
selves were neither permanent nor indestructible. In 1896 Becquerel had 
found that various substances containing uranium possessed the remark- 
able property, as it then appeared, of spontaneously affecting photographic 
plates in their vicinity. This observation led to the discoverv of a new 


property of matter, namely radio-activity. All the results obtained from 
the study of radio-activity in the few following years were co-ordinated 
in the hypothesis of "spontaneous disintegration" which Rutherford and 
Soddy advanced in 1903. According to this hypothesis in its present form, 
radio-activity indicates a spontaneous break-up of the nuclei of the atoms 
of radio-active substances. These atoms are so far from being permanent 
and indestructible that their very nuclei crumble away with the mere 
lapse of time, so that what was once the nucleus of a uranium atom is 
transformed, after sufficient time, into the nucleus of a lead atom. 

The process of transformation is not instantaneous; it proceeds grad- 
ually and by distinct stages. During its progress, three types of product are 
emitted, which are designated a-rays, (3-rays, and y-rays. 

These were originally described indiscriminately as rays because all 
three were found to have the power of penetrating through a certain 
thickness of air, metal, or other substance. It was not until later that their 
true nature was discovered. It is well known that magnetic forces, such 
as, for instance, occur in the space between the poles of a magnet, cause 
a moving particle charged with electricity to deviate from a straight 
course; the particle deviates in one direction or the other according as 
it is charged with positive or negative electricity. On passing the various 
rays emitted by radio-active substances through the space between the 
poles of a powerful magnet, the a-rays were found to consist of particles 
charged with positive electricity, and the P-rays to consist of particles 
charged with negative electricity. But the most powerful magnetic forces 
which could be employed failed to cause the slightest deviation in the 
paths of the y-rays, from which it was concluded that either the y-rays 
were not material particles at all, or that, if they were, they carried no 
electric charges. The former of these alternatives was subsequently proved 
to be the true one. 

a-p ARTICLES. The positively charged particles which constitute a-rays 
are generally described as a-particles. In 1909 Rutherford and Royds 
allowed a-particles to penetrate through a thin glass wall of less than a 
hundredth of a millimetre in thickness into a chamber from which they 
could not escape a sort of mouse-trap for a-particles. After the process 
had continued for a long time, the final result was not an accumulation 
of a-particles but an accumulation of the gas helium, the next simplest 
gas after hydrogen. In this way it was established that the positively 
charged a-particles are simply nuclei of helium atoms; the a-particles, 
being positively charged, had attracted negatively charged electrons to 
themselves out of the walls of the chamber and the result was a collection 
of complete helium atoms. 


The a-particles move with enormous speeds, which depend upon the 
nature of the radio-active substance from which they have been shot out. 
The fastest particles of all move with a speed of 12,800 miles a second; 
even the slowest have a speed of 8800 miles a second, which is about 
30,000 times the ordinary molecular velocity in air. Particles moving with 
such speeds as these knock all ordinary molecules out of their way; this 
explains the great penetrating power of the a-rays. 

(3-p ARTICLES. By examining the extent to which their motion was 
influenced by magnetic forces, the P-rays were found to consist of nega- 
tively charged electrons, exactly similar to those which surround the 
nucleus in all atoms. As an a-particle carries a positive charge equal in 
amount to that of two electrons, an atom which has ejected an a-particle 
is left with a deficiency of positive charge, or what comes to the same 
thing, with a negative charge, equal to that of two electrons. Consequently 
it is natural, and indeed almost inevitable, that the ejections of a-particles 
should alternate with an ejection of negatively charged electrons, in the 
proportion of one a-particle to two electrons, so that the balance of posi- 
tive and negative electricity in the atom may be maintained. The (3-parti- 
cles move with even greater speeds than the a-particles, many approaching 
to within a few per cent, of the velocity of light (186,000 miles a 
second). . . . 

Y-RAYS. As has already been mentioned, the y-rays are not material 
particles at all; they prove to be merely radiation of a very special kind. 

Thus the break-up of a radio-active atom may be compared to the 
discharge of a gun; the a-particle is the shot fired, the ^-particles are the 
smoke, and the y-rays are the flash. The atom of lead which finally 
remains is the unloaded gun, and the original radio-active atom, of 
uranium or what not, was the loaded gun. And the special peculiarity of 
radio-active guns is that they go of? spontaneously and of their own 
accord. All attempts to pull the trigger have so far failed, or at least have 
led to inconclusive results; we can only wait, and the gun will be found 
to fire itself in time. . . . 

In 1920, Rutherford, using radio-active atoms as guns, fired a-particles 
at light atoms and found that direct hits broke up their nuclei. There is, 
however, found to be a significant difference between the spontaneous 
disintegration of the heavy radio-active atoms and the artificial disintegra- 
tion of the light atoms; in the former case, apart from the ever-present 
P-rays and y-rays, only a-particles are ejected, while in the latter case 
a-particles were not ejected at all, but particles of only about a quarter 
their weight, which proved to be identical with the nuclei of hydrogen 
atoms. . . . 


ISOTOPES. Two atoms have the same chemical properties if the charges 
of positive electricity carried by their nuclei are the same. The amount of 
this charge fixes the number of electrons which can revolve around the 
nucleus, this number being of course exactly that needed to neutralise 
the electric field of the nucleus, and this in turn fixes the atomic number 
of the element. And it has for long been known that the weights of all 
atoms are, to a very close approximation, multiples of a single definite 
weight. This unit weight is approximately equal to the weight of the 
hydrogen atom, but is more nearly equal to a sixteenth of the weight 
of the oxygen atom. The weight of any type of atom, measured in terms 
of this unit, is called the "atomic weight" of the atom. 

It used to be thought that a mass of any single chemical element, such 
as mercury or xenon, consisted of entirely similar atoms, every one o 
which had not only the same atomic number but also the same atomic 
weight. But Dr. Aston has shewn very convincingly that atoms of the 
same chemical element, say neon or chlorine, may have nuclei of a great 
many different weights. The various forms which the atoms of the same 
chemical element can assume are known as isotopes being of course 
distinguished by their different weights. 

These weights are much nearer to whole numbers than were the old 
"atomic" weights of the chemists. For instance the atomic weight of 
chlorine used to be given as 35-5, and this was taken to mean that chlorine 
consisted of a mixture of atoms each 35-5 times as massive as the hydrogen 
atom. Aston finds that chlorine consists of a mixture of atoms of atomic 
weights 35 and 37 (or more accurately 34-983 and 36-980), the former being 
approximately three times as plentiful as the latter. In the same way a 
mass of mercury, of which the mean atomic weight is about 200-6, is 
found to be a mixture of seven kinds of atoms of atomic weights 196, 198, 
199, 200, 201, 202, 204. Tin is a mixture of no fewer than eleven isotopes 
112, 114, 115, 116, 117, 118, 119, 120, 121, 122, 124. 

PROTONS AND ELECTRONS. When the presence of isotopes is taken into 
account, the atomic weights of all atoms prove to be far nearer to integral 
numbers than had originally been thought. This, in conjunction with 
Rutherford's artificial disintegration of atomic nuclei, led to the general 
acceptance of the hypothesis that the whole universe is built up of only 
two kinds of ultimate bricks, namely, electrons and protons. Each proton 
carries a positive charge of electricity exactly equal in amount to the 
negative charge carried by an electron, but has about 1847 times the weight 
of the electron. Protons are supposed to be identical with the nucleus 
of the hydrogen atom, all other nuclei being composite structures in which 
both protons and electrons are closely packed together. For instance, the 


nucleus of the helium atom, the a-particle, consists of four protons and 
two electrons, these giving it approximately four times the weight of the 
hydrogen atom, and a resultant charge equal to twice that of the nucleus 
of the hydrogen atom. 

NEUTRONS. Until quite recently this hypothesis was believed to give 
a satisfactory and complete account of the structure of matter. Then in 
1931 two German physicists, Bothe and Becker, bombarding the light 
elements beryllium and boron with the very rapid a-particles emitted by 
polonium, obtained a new and very penetrating radiation which they 
were at first inclined to interpret as a kind of y-radiation. Subsequently 
Dr. Chad wick of Cambridge shewed that it possessed properties which 
were inconstant with this interpretation and made it clear that the radia- 
tion consists of material objects of a type hitherto unknown to science. 
To the greatest accuracy of which the experiments permit these objects 
are found to have the same mass as the hydrogen atom, while their very 
high penetrating power shews that if they have any electric charge at all, 
it can only be a minute fraction at most of the charge of the electron. 

Thus it seems likely that the radiation consists of uncharged particles 
of the same mass as the proton something quite new in a world which 
until recently was believed to consist entirely of charged particles. Chad- 
wick describes these new particles as "neutrons." Whether they are 
themselves fundamental constituents of matter or not remains to be seen. 
Chadwick has suggested that they may be composite structures, each 
consisting of a proton and electron in such close combination that they 
penetrate matter almost as freely as though they had no size at all. On the 
other hand Heisenberg has considered the possibility that the neutron 
may be fundamental, the nucleus of an atom being built up solely of 
positively charged protons and uncharged neutrons, while the negative 
electrons are confined to the regions outside the nucleus. On this view 
there are just as many protons in the nucleus as there are electrons outside 
the nucleus, the number of each being the atomic number of the element, 
while the excess of mass needed to make up the atomic weight is provided 
by the inclusion of the requisite number of neutrons in the nucleus. 
Isotopes of the same element differ of course merely in having different 
numbers of neutrons in their nuclei. 

Rutherford and other physicists have considered the further possibility 
that other kinds of neutrons, with double the mass of the hydrogen atom, 
may also occur in atomic nuclei, a hypothesis for which there seems to 
be considerable observational support. 

POSITIVE ELECTRONS. Even more revolutionary discoveries were to 
come. A few years ago it seemed a piece of extraordinary good luck that 
in the a-particles nature herself had provided projectiles of sufficient 


shattering power to smash up the nucleus of the atom and disclose its 
secrets to the observation of the physicist. More recently nature has been 
found to provide yet more shattering projectiles in the cosmic radiation 
which continually bombards the surface of the earth probably from 
outer space. This radiation has such a devastating effect on the atomic 
nuclei that it is difficult to make much of the resulting collection of frag- 
ments. It is, however, always possible to examine any debris, no matter 
how involved, by noticing how the constituent particles move when acted 
on by magnetic forces. 

In 1932 C. D. Anderson made observations which suggested that this 
debris contained, among other ingredients, particles having the same 
positive charge as the proton, but a mass only comparable with, and pos- 
sibly equal to, that of the electron. The existence of such particles has been 
confirmed by Blackett and Occhialini at Cambridge. The new particles 
may well be described as positively charged electrons, and so have been 
named "positrons." 

As these new particles are believed to emerge from atomic nuclei, it 
would seem plausible to suppose that they must be normal constituents 
of the nuclei. Yet the recent discovery of the neutron suggests other pos- 

We have already mentioned the hypothesis, advocated by Heisenberg 
and others, that the nucleus consists solely of neutrons and protons. Ander- 
son has suggested that the proton may not be a fundamental unit in the 
structure of matter, but may consist of a positron and a neutron in com- 
bination. Every nucleus would then contain only neutrons and positrons, 
and the positrons could be driven out by bombardment in the ordinary 

The objection to this view is that the debris of the nuclei shattered by 
cosmic radiation is found to contain electrons as well as positrons, the 
electrons emerging, so far as can be seen, from the same atomic nuclei as 
the positrons. This has led Blackett and Occhialini to propound the 
alternative hypothesis that the electrons and positrons are born in pairs as 
the result of the processes of bombardment and disintegration of atomic 
nuclei. At first this may seem a flagrant violation of all our views as to the 
permanence of matter, but we shall see shortly that it is entirely in accord 
with the present trend of physics. 

It seems fairly certain that the positron has at most but a temporary 
existence. For positrons do not appear to be associated with matter under 
normal conditions, although they ought to abound if they were being 
continually produced out of nuclei at anything like the rate which the 
observations of Blackett and Occhialini seem to indicate. They might of 


course rapidly disappear from view through entering into combination 
with negatively charged particles to form some sort of permanent stable 
structure, but it seems more probable, as Blackett and Occhialini them- 
selves suggest, that they disappear from existence altogether by combining 
with negative electrons. Just as a pair of electrons one positively charged 
and one negatively charged can be born out of nothing but energy, so 
they can die in one another's arms and leave nothing but energy behind. 
We shall discuss the underlying physical mechanism almost immediately. 
Before the existence of the positron had been observed, or even suspected 
experimentally, Professor Dirac of Cambridge had propounded a mathe- 
matical theory which predicted not only the existence of the positron, but 
also the way in which it ought to behave. Dirac's theory is too abstrusely 
mathematical to be explained here, but it predicts that a shower of posi- 
trons ought gradually to fade away by spontaneous combination with 
negative electrons, following the same law of decay as radio-active sub- 
stances. And the average life of a positron is predicted to be one of only 
a few millionths of a second, which amply explains why the positron can 
live long enough to be photographed in a condensation chamber, but not 
long enough to shew its presence elsewhere in the universe. 


We have so far discussed only the material constituents of matter: we 
have pictured the atom as being built up of some or all of the material 
ingredients which we have described as electrons, protons, neutrons and 
positrons. Yet this is not the whole story. If it were, every atom would 
consist of a certain number of protons and neutrons with just sufficient 
electrons and positrons to make the total electric charge equal to zero. 
Thus, apart from the insignificant weights of electrons and positrons, the 
weight of every atom would be an exact multiple of the weight of a 
hydrogen atom. Experiment shews this not to be the case. 

ELECTROMAGNETIC ENERGY. To get at the whole truth, we have to 
recognise that, in addition to containing material electrons and protons > 
with possible neutrons and positrons, the atom contains yet a further 
ingredient which we may describe as electromagnetic energy. We may 
think of this, although with something short of absolute scientific accuracy, 
as bottled radiation. 

If we disturb the surface of a pond with a stick, a series of ripples starts 
from the stick and travels, in a series of ever-expanding circles, over the 
surface of the pond. As the water resists the motion of the stick, we have 
to work to keep the pond in a state of agitation. The energy of this work 
is transformed, in part at least, into the energy of the ripples. We ca,n see 


that the ripples carry energy about with them, because they cause a floating 
cork or a toy boat to rise up against the earth's gravitational pull. Thus 
the ripples provide a mechanism for distributing over the surface of the 
pond the energy that we put into the pond through the medium of the 
moving stick. 

Light and all other forms of radiation are analogous to water ripples or 
waves, in that they distribute energy from a central source. The sun's 
radiation distributes through space the vast amount of energy which is 
generated inside the sun. We hardly know whether there is any actual 
wave motion in light or not, but we know that both light and all other 
types of radiation are propagated in such a form that they have many of 
the properties of a succession of waves. 

The different colours of light which in combination constitute sunlight 
can be separated out by passing the light through a prism, thus forming 
a rainbow or "spectrum" of colors. The separation can also be effected by 
an alternative instrument, the diffraction grating, which consists merely 
of a metal mirror with a large number of parallel lines scratched evenly 
across its surface. The theory of the action of this latter instrument is 
well understood; it shews that actually the light is separated into waves 
of different wave-lengths. (The wave-length in a system of ripples is the 
distance from the crest of one ripple to that of the next, and the term may 
be applied to all phenomena of an undulatory nature.) This proves that 
different colours of light are produced by waves of different lengths, and 
at the same time enables us to measure the lengths of the waves which 
correspond to the different colours of light. 

These prove to be very minute. The reddest light we can see, which is 


that of longest wave-length, has a wave-length of only inch 


(7.5 Xio" 5 cm.); the most violet light we can see has a wave-length only 
half of this, or 0-000015 inch. Light of all colours travels with the same 
uniform speed of 186,000 miles, or 3Xio 10 centimetres, a second. The 
number of waves of red light which pass any fixed point in a second is 
accordingly no fewer than four hundred million million. This is called 
the "frequency" of the light. Violet light has the still higher frequency 
of eight hundred million million; when we see violet light, eight hundred 
million million waves of light enter our eyes each second. 

The spectrum of analysed sunlight appears to the eye to stretch from 
red light at one end to violet light at the other, but these are not its true 
limits. When certain chemical salts are placed beyond the violet end of 
the visible spectrum, they are found to shine vividly, shewing that even 
out here energy is being transported, although in invisible form. And 


other methods make it clear that the same is true out beyond the red end 
of the spectrum. A thermometer, or other heat-measuring instrument, 
placed here will shew that energy is being received here in the form of 

In this way we find that regions of invisible radiation stretch indefi- 
nitely from both ends of the visible spectrum. From one end the red 
we can pass continuously to waves of the type used for wireless transmis- 
sion, which have wave-lengths of the order of hundreds, or even thousands, 
of yards. From the violet end, we pass through waves of shorter and ever 
shorter wave-length all the various forms of ultra-violet radiation. At 
wave-lengths of from about a hundredth to a thousandth of the wave- 
length of visible light, we come to the familiar X-rays, which penetrate 
through inches of our flesh, so that we can photograph the bones inside. 
Far out even beyond these, we come to the type of radiation which con- 
stitutes the Y-rays, its wave-length being of the order of 


inch, or only about a hundred-thousandth part of the wave-length of 
visible light. Thus the y-rays may be regarded as invisible radiation of 
extremely short wave-length. We shall discuss the exact function they 
serve later. For the moment let us merely remark that in the first instance 
they served the extremely useful function of fogging BecquereFs photo- 
graphic plates, thus leading to the detection of the radio-active property 
of matter. 

It is a commonplace of modern electromagnetic theory that energy of 
every kind carries weight about with it, weight which is in every sense as 
real as the weight of a ton of coal. A ray of light causes an impact on any 
surface on which it falls, just as a jet of water does, or a blast of wind, or 
the fall of a ton of coal; with a sufficiently strong light one could knock a 
man down just as surely as with the jet of water from a fire hose. This is 
not a mere theoretical speculation. The pressure of light on a surface has 
been both detected and measured by direct experiment. The experiments 
are extraordinarily difficult because, judged by all ordinary standards, the 
weight carried by radiation is exceedingly small; all the radiation emitted 
from a 50 horse-power searchlight working continuously for a century 
weighs only about a twentieth of an ounce. 

It follows that any substance which is emitting radiation must at the 
same time be losing weight. In particular, the disintegration of any radio- 
active substance must involve a decrease of weight, since it is accompanied 
by the emission of radiation in the form of Y-rays. The ultimate fate of an 
ounce of uranium may be expressed by the equation: 


f 0-8653 un ce lead, 

i ounce uranium =| 0-1345 " helium, 
[0-0002 " radiation. 

The lead and helium together contain just as many electrons and just 
as many protons as did the original ounce of uranium, but their combined 
weight is short of the weight of the original uranium by about one part 
in 4000. Where 4000 ounces of matter originally existed, only 3999 now 
remain; the missing ounce has gone off in the form of radiation. 

This makes it clear that we must not expect the weights of the various 
atoms to be exact multiples of the weight of the hydrogen atom; any 
such expectation would ignore the weight of the bottled-up electro-mag- 
netic energy which is capable of being set free and going off into space in 
the form of radiation as the atom changes its make-up. The weight of this 
energy is relatively small, so that the weights of the atoms must be ex- 
pected to be approximately, although not exactly, integral multiples of 
that of the hydrogen atom, and this expectation is confirmed. The exact 
weight of our atomic building is not simply the total weight of all its 
bricks; something must be added for the weight of the mortar the electro- 
magnetic energy which keeps the bricks bound together. 

Thus the normal atom consists of its material constituents protons, 
electrons, neutrons and positrons, or some at least of these and also of 
energy, which also contributes something to its weight. When the atom 
re-arranges itself, either spontaneously or under bombardment, protons 
and electrons, or other fragments of its material structure, may be shot off 
in the form of a- and (3-particles, and energy may also be set free in the 
form of radiation. This radiation may either take the form of y-rays, or 
of other forms of visible and invisible radiation. The final weight of the 
atom will be obtained by deducting from its original weight not only 
the weight of all the ejected electrons and protons, but also the weight 
of all the energy which has been set free as radiation. 


The series of concepts which we now approach are difficult to grasp 
and still more difficult to explain, largely, no doubt, because our minds 
receive no assistance from our everyday experience of nature. It becomes 
necessary to speak mainly in terms of analogies, parables and models which 
can make no claim to represent ultimate reality; indeed, it is rash to 
hazard a guess even as to the direction in which ultimate reality lies. 

The laws of electricity which were in vogue up to about the end of the 
nineteenth century the famous laws of Maxwell and Faraday required 


that the energy of an atom should continually decrease, through the atom 
scattering energy abroad in the form of radiation, and so having less and 
less left for itself. These same laws predicted that all energy set free in 
space should rapidly transform itself into radiation of almost infinitesimal 
wave-length. Yet these things simply did not happen, making it obvious 
that the then prevailing electrodynamical laws had to be given up. 

CAVITY-RADIATION. A crucial case of failure was provided by what is 
known as "cavity-radiation." A body with a cavity in its interior is heated 
up to incandescence; no notice is taken of the light and heat emitted by 
its outer surface, but the light imprisoned in the internal cavity is let out 
through a small window and analysed into its constituent colours by a 
spectroscope or diffraction grating. This is the radiation that is known 
as "cavity-radiation." It represents the most complete form of radiation 
possible, radiation from which no colour is missing, and in which every 
colour figures at its full strength. No known substance ever emits quite 
such complete radiation from its surface, although many approximate to 
doing so. We speak of such bodies as "full radiators." 

The nineteenth-century laws of electromagnetism predicted that the 
whole of the radiation emitted by a full radiator or from a cavity ought 
to be found at or beyond the extreme violet end of the spectrum, inde- 
pendently of the precise temperature to which the body had been heated. 
In actual fact the radiation is usually found piled up at exactly the op- 
posite end of the spectrum, and in no case does it ever conform to the 
predictions of the nineteenth century laws, or even begin to think of 
doing so. 

In the year 1900 Professor Planck of Berlin discovered experimentally 
the law by which cavity-radiation is distributed among the different 
colours of the spectrum. He further shewed how his newly-discovered law 
could be deduced theoretically from a system of electromagnetic laws 
which differed very sensationally from those then in vogue. 

Planck imagined all kinds of radiation to be emitted by systems of 
vibrators which emitted light when excited, much as tuning forks emit 
sound when they are struck. The old electrodynamical laws predicted 
that each vibration should gradually come to rest and then stop, as the 
vibrations of a tuning fork do, until the vibrator was in some way excited 
again. Rejecting all this, Planck supposed that a vibrator could change 
its energy by sudden jerks, and in no other way; it might have one, two, 
three, four or any other integral number of units of energy, but no inter- 
mediate fractional numbers, so that gradual changes of energy were 
rendered impossible. The vibrator, so to speak, kept no small change, 
and could only pay out its energy a shilling at a time until it had none 


left. Not only so, but it refused to receive small change, although it was 
prepared to accept complete shillings. This concept, sensational, revolu- 
tionary and even ridiculous, as many thought it at the time, was found to 
lead exactly to the distribution of colours actually observed in cavity-ra- 

In 1917 Einstein put the concept into the more precise form which now 
prevails. According to a theory previously advanced by Professor Niels 
Bohr of Copenhagen, an atomic or molecular structure does not change 
its configuration, or dissipate away its energy, by gradual stages; on the 
contrary, the changes are so abrupt that it is almost permissible to regard 
them as a series of sudden jumps or jerks. Bohr supposed that an atomic 
structure has a number of possible states or configurations which are 
entirely distinct and detached one from another, just as a weight placed 
on a staircase has only a possible number of positions; it may be 3 stairs 
up, or 4 or 5, but cannot be 3 % or 3% stairs up. The change from one 
position to another is generally effected through the medium of radiation. 
The system can be pushed upstairs by absorbing energy from radiation 
which falls on it, or may move downstairs to a state of lower energy and 
emit energy in the form of radiation in so doing. Only radiation of a 
certain definite colour, and so of a certain precise wave-length, is of any 
account for effecting a particular change of state. The problem of shifting 
an atomic system is like that of extracting a box of matches from a penny- 
in-the-slot machine; it can only be done by a special implement, to wit a 
penny, which must be of precisely the right size and weight a coin which 
is either too small or too large, too light or too heavy, is doomed to fail. 
If we pour radiation of the wrong wave length on to an atom, we may re- 
produce the comedy of the millionaire whose total wealth will not procure 
him a box of matches because he has not a loose penny, or we may re* 
produce the tragedy of the child who cannot obtain a slab of chocolate 
because its hoarded wealth consists of farthings and half-pence, but we 
shall not disturb the atom. When mixed radiation is poured on to a col- 
lection of atoms, these absorb the radiation of just those wave-lengths 
which are needed to change their internal states, and none other; radiation 
of all other wave-lengths passes by unaffected. 

This selective action of the atom on radiation is put in evidence in a 
variety of ways; it is perhaps most simply shewn in the spectra of the sun 
and stars. Dark lines similar to those which Fraunhofer observed in the 
solar spectrum are observed in the spectra of practically all stars and we 
can now understand why this must be. Light of every possible wave-length 
streams out from the hot interior of a star, and bombards the atoms which 
form its atmosphere. Each atom drinks up that radiation which is of 


precisely the right wave-length for it, but has no interaction of any kind 
with the rest, so that the radiation which is finally emitted from the star 
is deficient in just the particular wave-lengths which suit the atoms. Thus 
the star shews an absorption spectrum of fine lines. The positions of these 
lines in the spectrum shew what types of radiation the stellar atoms have 
swallowed, and so enable us to identify the atoms from our laboratory 
knowledge of the tastes of different kinds of atoms for radiation. But 
what ultimately decides which types of radiation an atom will swallow, 
and which it will reject? 

It had been part of Planck's theory that radiation of each wave-length 
has associated with it a certain amount of energy, called the "quantum," 
which depends on the wave-length and on nothing else. The quantum 
is supposed to be proportional to the "frequency," or number of vibrations 
of the radiation per second, and so is inversely proportional to the wave- 
length of the radiation the shorter the wave-length, the greater the 
energy of the quantum, and conversely. Red light has feeble quanta, violet 
light has energetic quanta, and so on. 

Einstein now supposed that radiation of a given type could effect an 
atomic or molecular change, only if the energy needed for the change 
is precisely equal to that of a single quantum of the radiation. This is 
commonly known as Einstein's law; it determines the precise type of 
radiation needed to work any atomic or molecular penny-in-the-slot 

We notice that work which demands one powerful quantum cannot 
be performed by two, or indeed by any number whatever, of feeble quanta. 
A small amount of violet (high-frequency) light can accomplish what no 
amount of red (low-frequency) light can effect. 

The law prohibits the killing of two birds with one stone, as well as 
the killing of one bird with two stones; the whole quantum is used up in 
effecting the change, so that no energy from this particular quantum is 
left over to contribute to any further change. This aspect of the matter is 
illustrated by Einstein's photochemical law: "in any chemical reaction 
which is produced by the incidence of light, the number of molecules 
which are affected is equal to the number of quanta of light which are 
absorbed." Those who manage penny-in-the-slot machines are familiar 
with a similar law: "the number of articles sold is exactly equal to the 
number of coins in the machine." 

If we think of energy in terms of its capacity for doing damage, we see 
that radiation of short wave-length can work more destruction in atomic 
structures than radiation of long wave-lengtha circumstance with 
which every photographer is painfully familiar; we can admit as much 


red light as we please without any damage being done, but even the 
tiniest gleam of violet light spoils our plates. Radiation of sufficiently 
short wave-length may not only rearrange molecules or atoms; it may 
break up any atom oa which it happens to fall, by shooting out one of 
its electrons, giving rise to what is known as photoelectric action. Again 
there is a definite limit of frequency, such that light whose frequency 
is below this limit does not produce any effect at all, no matter how in- 
tense it may be; whereas as soon as we pass to frequencies above this 
limit, light of even the feeblest intensity starts photoelectric action at 
once. Again the absorption of one quantum breaks up only one atom, 
and further ejects only one electron from the atom. If the radiation has 
a frequency above this limit, so that its quantum has more energy than 
the minimum necessary to remove a single electron from the atom, the 
whole quantum is still absorbed, the excess energy now being used in 
endowing the ejected electron with motion. 

ELECTRON ORBITS. These concepts are based upon Bohr's supposition 
that only a limited number of orbits are open to the electrons in an atom, 
all others being prohibited for reasons which Bohr's theory did not fully 
explain, and that an electron is free to move from one permitted orbit 
to another under the stimulus of radiation. Bohr himself investigated the 
way in which the various permitted orbits are arranged. Modern investi- 
gations indicate the need for a good deal of revision of his simple concepts, 
but we shall discuss these in some detail, partly because Bohr's picture of 
the atom still provides the best working mechanical model we have, and 
partly because an understanding of his simple theory is absolutely es- 
sential to the understanding of the far more intricate theories which are 
beginning to replace it. 

The hydrogen atom, as we have already seen, consists of a single proton 
as central nucleus, with a single electron revolving around it. The nucleus, 
with about 1847 times the weight of the electron, stands practically at 
rest unagitated by the motion of the latter, just as the sun remains practi- 
cally undisturbed by the motion of the earth round it. The nucleus and 
electron carry charges of positive and negative electricity, and therefore 
attract one another; this is why the electron describes an orbit instead of 
flying of? in a straight line, again like the earth and sun. Furthermore, 
the attraction between electric charges of opposite sign, positive and 
negative, follows, as it happens, precisely the same law as gravitation, 
the attraction falling off as the inverse square of the distance between the 
two charges. Thus the nucleus-electron system is similar in all respects 
to a sun-planet system, and the orbits which an electron can describe 
around a central nucleus are precisely identical with those which a planet 


can describe about a central sun; they consist of a system of ellipses each 
having the nucleus in one focus. 

Yet the general concepts of quantum-dynamics prohibit the electron 
from moving in all these orbits indiscriminately. Bohr's original theory 
supposed that the electron in the hydrogen atom could move only in 
certain circular orbits whose diameters were proportional to the squares 
of the natural numbers, and so to i, 4, 9, 16, 25, .... Bohr subsequently 
modified this very simple hypothesis, and the theory of wave-mechanics 
has recently modified it much further. 

Yet it still remains true that the hydrogen atom has always very approxi- 
mately the same energy as it would have if the electron were describing 
one or another of these simple orbits of Bohr. Thus, when its energy 
changes, it changes as though the electron jumped over from one to another 
of these orbits. For this reason it is easy to calculate what changes of 
energy a hydrogen atom can experience they are precisely those which 
correspond to the passage from one Bohr orbit to another. For example, 
the two orbits of smallest diameters in the hydrogen atom differ in energy 
by i6Xio~ 12 erg. If we pour radiation of the appropriate wave-length on 
to an atom in which the electron is describing the smallest orbit of all, it 
crosses over to the next orbit, absorbing i6Xio" 12 erg of energy in the 
process, and so becoming temporarily a reservoir of energy holding 16 
X io" 12 erg. If the atom is in any way disturbed from outside, it may of 
course discharge the energy at any time, or it may absorb still more 
energy and so increase its store. 

If we know all the orbits which are possible for an atom of any type, it 
is easy to calculate the changes of energy involved in the various transi- 
tions between them. As each transition absorbs or releases exactly one 
quantum of energy, we can immediately deduce the frequencies of the 
light emitted or absorbed in these transitions. In brief, given the arrange- 
ment of atomic orbits, we can calculate the spectrum of the atom. In 
practice the problem of course takes the converse form: given the spec- 
trum, to find the structure of the atom which emits it. Bohr's model of 
the hydrogen atom is a good model at least to this extent that the spec- 
trum it would emit reproduces the hydrogen spectrum almost exactly. 
Yet the agreement is not quite perfect, and for this reason it is now 
generally accepted that Bohr's scheme of orbits is inadequate to account 
for actual spectra. We continue to discuss Bohr's scheme, not because the 
atom is actually built that way, but because it provides a working model 
which is good enough for our present purpose. 

An essential, although at first sight somewhat unexpected, feature of 
the whole theory is that even if the hydrogen atom charged with its 


16 X io" 12 erg of energy is left entirely undisturbed, the electron must, 
after a certain time, lapse back spontaneously to its original smaller orbit, 
ejecting its 16 X io" 12 erg of energy in the form of radiation in so doing. 
Einstein shewed that, if this were not so, then Planck's well-established 
"cavity-radiation" law could not be true. Thus, a collection of hydrogen 
atoms in which the electrons describe orbits larger than the smallest pos- 
sible orbit is similar to a collection of uranium or other radio-active atoms, 
in that the atoms spontaneously fall back to their states of lower energy 
as the result merely of the passage of time. 

The electron orbits in more complicated atoms have much the same 
general arrangement as in the hydrogen atom, but are different in size. 
In the hydrogen atom the electron normally falls, after sufficient time, to 
the orbit of lowest energy and stays there. It might be thought by analogy 
that in more complicated atoms in which several electrons are describing 
orbits, all the electrons would in time fall into the orbit of lowest energy 
and stay there. Such does not prove to be the case. There is never room 
for more than one electron in the same orbit. This is a special aspect of 
a general principle which appears to dominate the whole of physics. It 
has a name "the exclusion-principle" but this is about all as yet; we have 
hardly begun to understand it. In another of its special aspects it becomes 
identical with the old familiar cornerstone of science which asserts that 
two different pieces of matter cannot occupy the same space at the same 
time. Without understanding the underlying principle, we can accept 
the fact that two electrons not only cannot occupy the same space, but 
cannot even occupy the same orbit. It is as though in some way the electron 
spread itself out so as to occupy the whole of its orbit, thus leaving 
room for no other. No doubt this must not be accepted as a literal 
picture of things, and yet the modern theory of wave-mechanics sug- 
gests that in some sense (which we cannot yet specify with much pre- 
cision) the orbits of lowest energy in the hydrogen atom are possible orbits 
just because the electron can completely fill them, and that adjacent orbits 
are impossible because the electron would fill them t or ii times over, 
and similarly for more complicated atoms. In this connection it is per- 
haps significant that no single known phenomenon of physics makes it 
possible to say that at a given instant an electron is at such or such a 
point in an orbit of lowest energy; such a statement appears to be quite 
meaningless and the condition of an atom is apparently specified with 
all possible precision by saying that at a given instant an electron is in 
such an orbit, as it would be, for instance, if the electron had spread 
itself out into a ring. We cannot say the same of other orbits. As we pass 
to orbits of higher energy, and so of greater diameter, the indeterminate- 


ness gradually assumes a different form, and finally becomes of but little 
importance. Whatever form the electron may assume while it is describ- 
ing a little orbit near the nucleus, by the time it is describing a very 
big orbit far out it has become a plain material particle charged with 

Thus, whatever the reason may be, electrons which are describing orbits 
in the same atom must all be in different orbits. The electrons in their 
orbits are like men on a ladder; just as no two men can stand on the 
same rung, so no two electrons can ever follow one another round in the 
same orbit. The neon atom, for instance, with 10 electrons is in its normal 
state of lowest energy when its 10 electrons each occupy one of the 10 
orbits whose energy is lowest. For reasons which the quantum theory has 
at last succeeded in elucidating, there are, in every atom, two orbits in 
which the energy is equal and lower than in any other orbit. After this 
come eight orbits of equal but substantially higher energy, then 18 orbits 
of equal but still higher energy, and so on. As the electrons in each 
of these various groups of orbits all have equal energy, they are commonly 
spoken of, in a graphic but misleading phraseology, as rings of electrons. 
They are designated the K-ring, the L-ring, the M-ring and so on. 
The ,K-ring, which is nearest to the nucleus, has room for two electrons 
only. Any further electrons are pushed out into the L-ring, which has room 
for eight electrons, all describing orbits which are different but of equal 
energy. If still more electrons remain to be accommodated, they must 
go into the M-ring and so on. 

In its normal state, the hydrogen atom has one electron in its K~ring, 
while the helium has two, the L, M, and higher rings being unoccupied. 
The atom of next higher complexity, the lithium atom, has three electrons, 
and as only two can be accommodated in its X-ring, one has to wander 
round in the outer spaces of the L-ring. In beryllium with four electrons, 
two are driven out into the L-ring. And so it goes on, until we reach 
neon with 10 electrons, by which time the L-ring as well as the inner X- 
ring is full up. In the next atom, sodium, one of the n electrons is 
driven out into the still more remote M-ring, and so on. Provided the 
electrons are not being excited by radiation or other stimulus, each atom 
sinks in time to a state in which its electrons are occupying its orbits of 
lowest energy, one in each. 

So far as our experience goes, an atom, as soon as it reaches this 
state, becomes a true perpetual motion machine, the electrons continuing 
to move in their orbits (at any rate on Bohr's theory) without any of 
the energy of their motion being dissipated away, either in the form of 
radiation or otherwise. It seems astonishing and quire incomprehensible 


that an atom in such a state should not be able to yield up its energy 
still further, but, so far as our experience goes, it cannot. And this 
property, little though we understand it, is, in the last resort, responsible 
for keeping the universe in being. If no restriction of this kind inter- 
vened, the whole material energy of the universe would disappear in 
the form of radiation in a few thousand-millionth parts of a second. If the 
normal hydrogen atom were capable of emitting radiation in the way 
demanded by the nineteenth-century laws of physics, it would, as a direct 
consequence of this emission of radiation, begin to shrink at the rate of 
over a metre a second, the electron continually falling to orbits of lower 
and lower energy. After about a thousand-millionth part of a second the 
nucleus and the electron would run into one another, and the whole atom 
would probably disappear in a flash of radiation. By prohibiting any 
emission of radiation except by complete quanta, and by prohibiting any 
emission at all when there are no quanta available for dissipation, the 
quantum theory succeeds in keeping the universe in existence as a going 

It is difficult to form even the remotest conception of the realities under- 
lying all these phenomena. The recent branch of physics known as 
"wave mechanics" is at present groping after an understanding, but so 
far progress has been in the direction of co-ordinating observed phenomena 
rather than in getting down to realities. Indeed, it may be doubted 
whether we shall ever properly understand the realities ultimately in- 
volved; they may well be so fundamental as to be beyond the grasp of the 
human mind. 

It is just for this reason that modern theoretical physics is so difficult 
to explain, and so difficult to understand. It is easy to explain the motion 
of the earth round the sun in the solar system. We see the sun in the 
sky; we feel the earth under our feet, and the concept of motion is 
familiar to us from everyday experience. How different when we try 
to explain the analogous motion of the electron round the proton in 
the hydrogen atom! Neither you nor I have any direct experience of 
either electrons or protons, and no one has so far any inkling of what 
they are really like. So we agree to make a sort of model in which the 
electron and proton are represented by the simplest things known to us, 
tiny hard spheres. The model works well for a time and then suddenly 
breaks in our hands. In the new light of the wave mechanics, the hard 
sphere is seen to be hopelessly inadequate to represent the electron. A hard 
sphere has always a definite position in space; the electron apparently 
has not. A hard sphere takes up a very definite amount of room, an 
electron well, it is probably as meaningless to discuss how much room an 


electron takes up as it is to discuss how much room a fear, an anxiety or 
an uncertainty takes up, but if we are pressed to say how much room 
an electron takes up, perhaps the best answer is that it takes up the whole 
of space. A hard sphere moves from one point to the next; our model 
electron, jumping from orbit to orbit in Bohr's model hydrogen atom, 
certainly does not behave like any hard sphere of our waking experience, 
and the real electron if there is any such thing as a real electron 
probably even less. Yet as our minds have so far failed to conceive any 
better picture of the atom than this very imperfect model, we can only 
proceed by describing phenomena in terms of it. 

Edition of 1934 

Touring the Atomic World 


do at the moment why not go on a trip into an invisible world ? No 
money is required, no packing, or long, tiresome rides. Just a fertile imag- 
ination. Pick up an object, any object, and look at it. Then imagine that 
you are slowly shrinking in size. Say the object you are holding is a white 
handkerchief. As you shrink, the handkerchief seems to expand enor- 
mously. At first it looks as big as a circus tent. But you're still becoming 
smaller. Now as you stand on the handkerchief, it forms a great, white 
plain as far as your eye can see. Still you grow smaller, and you become 
aware that great cracks are opening in your white plain. These aren't the 
result of an earthquake, nor the crevasses in a glacier. They simply prove 
that no matter how tightly woven your handkerchief may seem to be there 
are spaces between the threads. As you grow smaller still, the spaces seem 
to widen and the threads, themselves, become larger. You can sit on one 
now and hang your feet over the side. 


The thread seems to be a very safe place. Soon you can wander around 
on top of it, looking over the side and enjoying your trip to the utmost. 
But there are still surprises to come. As yet you aren't even within sight 
of the invisible world you have started out to visit. Still, you're getting 
there. For now the ground or rather the thread is beginning to open up 
beneath your feet. You see, you're still diminishing in size. In comparison, 
the thread is still becoming larger. Now you're beginning to find from 
first hand experience that threads are made up of fibers. And there are 
spaces between the fibers, just as there are between the threads. So you 
pick your way carefully along first one fiber and then another, being care- 
ful not to fall into the canyons between them. This seems easy until you 
find that the fibers themselves are beginning to show gaps. The one that 
at first was just a platform on which you stood is now assuming giant 
proportions, stretching away in all directions. You seem to be getting so 
small that you can just sink right through it. And that's exactly what is 
happening, for you slip through the surface of the fiber, disappear into it. 
And the next thing you know you're falling through space, like someone 
pitched out of a Buck Rogers spaceship. 

As you fall, you see all about you planets and suns and moons. They are 
arranged into tight little solar systems. And then, if you know your atomic 
physics, you'll realize that you have arrived in the hitherto invisible world 
of the atoms. You are falling through an ultramicroscopic universe, peo- 
pled by solar systems so infinitesimal that billions of them are contained 
in the fiber you have just slipped through. Yet there is still room for your 
much shrunken body to pass without even grazing them. Now you can 
pick out those sections of the atom that you were told about in school. 
You can see the bodies that look like planets and moons rotating around a 
central sun. You know that those are the electrons, electrical particles hav- 
ing a negative electrical charge. Then you turn your attention to the cen- 
tral sun, itself. You know that this is the nucleus of the atom, the impor- 
tant central mass that determines the character of the entire atomic solar 
system. It is made up of a number of different particles, known variously 
as protons, mesotrons, and neutrons. You can see all these things. But, 
unfortunately, that is as far as you can go. You cannot explore them 
freely as you have explored the handkerchief. For such a journey you need 
a special passport available to only a few men on earth. Even they have 
not yet developed the last passport of all, the one that will allow them to 
solve all the mysteries of the nucleus of the atom. 

The man who has come closest to making the entire trip through the 
invisible atomic world is Dr. Ernest O. Lawrence, developer of the world 
famous cyclotron on the University of California campus and winner of 


that most coveted award, the Nobel Prize in Physics for 1939. Shake off 
your imaginative spell, come back to your normal size, and let's go over 
the story of Dr. Lawrence's trips into the atomic unknown. After your 
journey you have the proper perspective to appreciate the difficulties he 
and his colleagues have overcome and those they hope to overcome in the 
near future. You know now from your own experience that nothing we 
can see in this world of ours is solid no matter how it feels to the touch. 
Everything we use, everything that we see, feel, touch, or taste is made 
in the final analysis, not of those things that we call paper, or sugar, or salt, 
or wood, but of tiny solar systems, called atoms, ultramicroscopic worlds 
which no one yet has ever completely explored, but which hold the secret 
to a possible re-making of our world in the forms which we desire. So, 
having familiarized yourself with the invisible world through your imag- 
inative journey, take another mind's eye tour with the writer, this time 
to the University of California campus where in the Radiation Laboratory 
we pick up the story of one of science's most valuable and remarkable 
developments, the cyclotron. 

This machine, now copied in all parts of the world, was first set in oper- 
ation at the University in 1929. It was the answer to a physicist's dream 
and proof of the old saw that necessity is the mother of invention. Physi- 
cists had been interested in atoms for many years. They knew about their 
arrangement with the electrons whirling in orbits about the central 
nucleus. They also knew that the proportion of negative and positive 
charges in the nucleus and the number of these charges present (in other 
words, the pattern and size of the nucleus) determined whether the atom 
was one of hydrogen gas, carbon, gold, iron, molybdenum, or some other 
element. However, this knowledge was not enough. What the physicists 
wanted to do was to tear the atomic world apart and see what made it tick. 
This, as they knew, was by no means an easy task. 

The atom is like a case-hardened steel safe without lock or combination. 
You can break into it only by main force and its resistance is powerful. 
Around itself it sets up a field of force which presents a stout barricade 
against invasion. The nucleus is tightly held together by the mutual elec- 
trical attraction of the particles from which it is formed. This sets up a 
second barrier. And, finally, the atom's lack of size works to the disadvan- 
tage of anyone attempting to explore its mysteries. After your imagina- 
tive journey through the handkerchief, you probably won't be surprised 
to find that atoms are so small it would take the entire population of the 
earth ten thousand years to count the number of them in a drop of water. 
Even then each individual counter would have to be reduced to one-bil- 
lionth of an inch in height in order to see an atom. At that he would be 


several cuts larger than you were when you fell through the fiber into the 
atomic universe. So you see the atom's lack of size presents a real prob- 
lem. The use of any ordinary weapon in an assault on the nucleus would 
be like using a sledge hammer to break into a grain of dust. What is 
required is some force small enough to enter the atom and still powerful 
enough to break down the electrical barricades surrounding it. 

Lord Rutherford, the famous English physicist, found such a force in 
the natural rays emitted by radium. These are called "alpha rays" by the 
scientists and are composed of steady streams of helium atoms thrown out 
at a pace of approximately 10,000 miles per second. They are caused by the 
disintegration of the radium. In 1919 Lord Rutherford used these rays to 
perform the first known transmutation of elements; or the act of changing 
one element into another. The ancient alchemists tried to perform trans- 
mutation by heating base metals with what they called "philosopher's 
stone" to produce gold. Much to their dismay gold was never produced. 
Lord Rutherford went about his transmutation operations in quite a dif- 
ferent way. He sent "alpha rays" crashing into the nuclei of nitrogen gas 
atoms and, after the shooting was over, out came oxygen. This may seem 
complicated but it was really very simple. All that happened was that the 
"alpha rays" crashing into the nitrogen atoms knocked a few particles out 
of their nuclei. The nature of any element is dependent upon the size and 
pattern of its nucleus, and the nuclei of the nitrogen atoms were so rear- 
ranged that a new element, oxygen, was formed. 

The success of Lord Rutherford's experiments set physicists all over the 
world at bombarding atoms with the rays of radium. Soon they found 
that when atomic nuclei were rearranged under the impact of a flying 
particle, tremendous amounts of energy were released. This energy, it 
appeared, was locked up inside the atom, and, when a few particles were 
split off the nucleus, some of the power leaked out. A little of it would go 
a long, long way. For the sub-atomic energy, as the power is called, locked 
up in the nuclei of the atoms in a fraction of a pint of water would drive 
a battleship from New York to Liverpool and back again. Physicists were 
greatly intrigued by the knowledge that some of this energy could be 
released by bombarding and partially breaking up the nuclei of atoms. It 
revived the hope that some day atomic energy of which there is a great 
and unfailing source might be used, instead of steam or electricity, to turn 
the wheels of the world's factories. 

Yet for all their speculation as to what these discoveries might mean 
the physicists still knew that radium was not the ideal atom-blaster they 
sought. They were really in the same position as the medical men before 
the invention of the microscope, and the astronomers before the invention 


of the telescope. These two inventions revolutionized medicine and 
astronomy. The physicists stood on the threshold of discoveries that would 
revolutionize our knowledge of the structure of the world and everything 
that lives on it. They needed another passport into the unknown. Radium 
had provided them with entry into the problem. But radium was too 
expensive for one thing and also it was not a very copious source of "alpha 
rays." A search began for some other method of smashing atoms, and thus 
the stage was set for Dr. E. O. Lawrence and his now-famous cyclotron. 

Lawrence, who was only beginning his University career at that time, 
had abandoned the idea of searching for some 'force strong enough nat- 
urally to break into the atomic citadel. Instead he proposed to take some 
weaker force and step it up by degrees until finally when unleashed, it 
could overpower the atom's defense. Or at least storm a -section of the 
barricade. To test his theory he built the first cyclotron, an almost pocket- 
sized model. It worked, as did a series of other slightly larger ones. So Dr. 
Lawrence began laying his plans for a machine that could really generate 
some power. The old Federal Telegraph Company had been forced in 
1918 to abandon its plans for constructing a wireless station in China. As 
a result, Federal still had a 6o-ton magnet on* its hands. Dr. Leonard F. 
Fuller, then vice-president of Federal and in his' first year as -chairman of 
the department of electrical engineering at the University, persuaded the 
board of directors to give the magnet to Dr. Lawrence. Around it the 
young physicist built an 85-ton cyclotron, the first really efficient atom- 
smasher the world was to know. 

Of course, Dr. Lawrence and his co-workers at the Radiation Labora- 
tory had no inkling that they were about to turn the physical world topsy- 
turvy. They just hoped the monster would work as well in fact as it did 
on paper. 

On paper it was all very simple. First, a circular chamber was placed 
between the poles of the magnet. Then all air was removed from the 
chamber and heavy hydrogen gas allowed to- flow in. This so-called heavy 
hydrogen behaves in the same way as ordinary hydrogen. However, while 
the nuclei of ordinary hydrogen atoms contain one positively charged par- 
ticle, or proton, heavy hydrogen nuclei contain two such particles plus 
one electron. Consequently, they weigh just twice as much as the nuclei 
of ordinary hydrogen atoms. They are known as deuterons. 

The deuteron's added weight makes it an ideal atomic bullet. And here 
is how Dr. Lawrence planned to send streams of deuterons crashing into 
the nuclei of other atoms in a constant, destructive barrage: Inside the 
cyclotron chamber was a heated filament that emitted streams of elec- 
trons. These particles would collide with the electrons surrounding the 


nuclei of the hydrogen atoms and in the ensuing mixup the nuclei and 
their satellites would become separated. The deuterons would be left free 
to float around the chamber. Eventually, the magnetic force set up by the 
cyclotron's magnet would pull them between two metal grids separated 
by a space across which an alternating electrical current of ten or fifteen 
thousand volts would be operating. As the deuterons floated into this 
space, they would receive a heavy shock, and under this stimulus fly off 
to'ward the side of the chamber. But the magnetic field would pull them 
back again in a semi-circular path until they again came between the two 
grids. Again they would be shocked and be sent flying out toward the 
side. Ancl again the magnet would pull them back to complete one full 
circle of the chamber and be shocked again. 

At each jolt from the current the deuterons would gather more energy. 
This meant that they would go flying out from between the grids with 
constantly increasing force and in constantly widening circles. So you get 
the picture of the atomic bullets receiving shocks one right after thfe^other 
from a weak electrical force. Each time the bullets receive a shock their 
energy is increased and they go on, describing wider and wider circles 
around the cyclotron chamber. Finally, they circle so widely that they 
reach a slit in the chamber wall and go flying out into the open air. The 
whole secret of the thing lies in making sure by means of the magnet that 
the atomic bullets are forced to come back for successive shocks until their 
energy is built up to the point where they can force their way to the exit. 
Dr. Lawrence figured that to bombard any substance with his atomic bul- 
lets, all he had to do was clamp this substance over the slit and let the 
onrushing stream of deuterons crash into it. This then was the theory put 
to the crucial test in 1934 at the University Radiation Laboratory. Dr. 
Lawrence threw the switch that sent a high-powered radio transmitter 
pumping energy into the cyclotron and the first experiment with the 85- 
ton machine had begun. 

If he and his colleagues held their collective breath during the first test, 
the results soon showed that their fear$ were without grounds. Within a 
short time, physicists were amazed to hear that Lawrence and his cyclo- 
tron were not only changing familiar elements like platinum, into other 
elements, like iridium and gold, but were actually producing substances 
never before seen on earth. These were the artificially radioactive ele- 
ments. Perhaps their character is best explained by illustration. 

One of the experiments performed with the cyclotron involved the bom- 
bardment of iron atoms with the high-speed deuterons produced by the 
cyclotron. When the deuterons crashed into them with a force of about 
eight million volts, the iron atoms were broken up. Some changed into 


atoms of cobalt or manganese. But others were converted into a new form 
of iron which, like radium, emitted streams of electrically charged par- 
ticles. In other words, this new iron was radioactive. Thirty-four different 
elements were subjected to bombardment with the 85-ton cyclotron and 
all of them underwent a transformation, many turning into radioactive 
substances. Among the artificial radioactive materials produced by the 
cyclotron were sodium, phosphorus, iron, and iodine. It was even pos- 
sible by bombarding bismuth to produce a degenerate form of radium, 
called Radium E. 

Another interesting product of these atomic bombardments was the 
neutron, a particle often found in the atomic nucleus. It adds to the weight 
of the nucleus but has no electrical charge, hence its name. When atoms 
were smashed by the bullets from the cyclotron, they flew into two parts. 
One might be an atom of a new radioactive element, and the other an 
atom of a light element such as hydrogen or helium. But more often than 
either of these two, a neutron would appear. When the cyclotron was 
going full blast, ten billion of these particles could be liberated every 

While neutrons are important as building-blocks of nature, they are 
also worthy of notice for their ability to destroy matter. A fast neutron 
rolling along at the speed of light has tremendous penetrating power. 
So great is this power, in fact, that even though the 225-ton machine is 
surrounded by lead water tanks and tin cans full of water and is inside 
a laboratory with thick concrete walls neutrons produced by its atomic 
bombardments have been detected as far as 100 yards from the building. 
When the neutrons are slowed up by passage through a sheet of paraffine, 
they lose part of their penetrating power, at the same time gaining tre- 
mendously in their ability to smash anything placed in their path. 
Physicists have taken advantage of this phenomenon. They are using 
slow neutrons for many experiments in which a high-powered sub- 
atomic bullet is required. 

At present the slow neutron is the bully boy being groomed for the 
final day when physicists hope to break into the treasure-house of atomic 

To continue his research on the fundamental problem of atomic struc- 
ture Dr. Lawrence plans to build a 4900-ton cyclotron, approximately 
twenty-two times as large as the 225-ton machine which is itself the 
largest atom-smasher of its kind in the world. This monster would cost 
from a million to a million and a half dollars. This is a great deal of 
money but let's see what it would buy. . . . 


Dr. Lawrence points out that even the tremendously powerful atomic 
bullets thrown out by the 225-ton cyclotron have not yet forced a com- 
plete capitulation of the atomic citadel. They can split off only a few of 
the particles of the nucleus. Before physicists can solve the fundamental 
problem of the forces that bind together the atomic nucleus it is necessary 
that this tight little core of the atom be completely torn apart. An atomic 
"explosion" must be provoked. 

. . . The laboratory in which these tremendous forces will be unleashed 
for atomic study will be placed far from the campus proper. We have 
already seen how the 225-ton cyclotron produces rays that pass through 
thick lead tanks full of water, through the concrete sides of the Radiation 
Laboratory, and out for more than 100 yards across the campus of the 
University. These forces are relatively weak in comparison with those 
that would be produced by a 4900-ton machine. Probably no practicable 
amount of artificial sheathing would cut down the radiation reaching the 
outside sufficiently. So the plans now are to place the machine and the 
laboratory in a great building in Strawberry Canyon in the Berkeley 
Hills. Then at least 500 feet will separate the cyclotron from its innocent 
neighbors. To protect the laboratory staff from the tremendous amount 
of radiation that will be produced, the machine will be surrounded by 
lead water jackets 15 feet thick. It is possible also that the control room 
may be placed underground so that the earth will provide an additional 
buffer between the cyclotron and its operators. 

In the higher energy ranges within reach of the 4900-ton cyclotron 
and with the much more powerful atomic bullets produced by this tre- 
mendous machine entirely new forms of radiation and entirely new sub- 
stances will be produced and put to the service of mankind. Identity of 
these radiations and substances can only be guessed at but certainly they 
will prove of the greatest importance not only as additions to our funda- 
mental knowledge of the behavior of atoms but also as contributions to 
industry, biology, and medicine. It may be possible with the 4900-ton 
cyclotron to transmute any element into another at will, to produce any 
known substance and many new ones to order. This would give us com- 
plete mastery of all the physical elements. Still it wouldn't touch the pos- 
sibilities of the achievement Dr. Lawrence is really working toward: lib- 
eration of the power contained in the atomic nucleus. 

Let's review again the facts concerning this power. The nucleus makes 
up more than 99 per cent of the mass of the atom and contains more than 
99 per cent of the atom's energy. This store of energy has never been 
tapped for useful purposes. Nevertheless, we know it must be tremen- 
dous. Radium releases enough energy to raise its own weight in water tc 


the boiling point every hour and it continues to give off this energy for 
thousands of years. Nor is radium unique. Locked within the nuclei of 
commoner and less expensive elements are like funds of power. At the 
Radiation Laboratory Dr. Malcolm Henderson, a physicist on leave from 
Princeton University, bombarded 13 grams of uranium. He found that 
each uranium atom he was able to split gave off 175,000,000 electron volts 
of energy. From those results he calculated that eight pounds of uranium 
contain as much power as 6,300 tons of fuel oil, and that a little over a 
half-pound of uranium would warm a ton of water to 3,860,000 degrees 
Centigrade, or convert 386,000 tons of ice water into boiling water. If 
such vast amounts of energy could be released and harnessed for practical 
purposes we would never again have to worry over depletion of our sup- 
plies of coal and oil. Conservation of natural resources would become but 
an empty phrase that once was popular when men still depended upon 
minerals for power and heat. 

Now how to release this energy? You'll remember our sub-atomic 
bruiser, the slow neutron. On his shoulders rest the hopes of Dr. Lawrence 
and his Radiation Laboratory staff. Here is how they hope to put him to 
work. First, they will build up the power in the 49Oo-ton cyclotron until it 
is producing streams of deuterons or helium atoms carrying energies of 
more than 100 million volts. These charged particles will be sent crashing 
into some element, probably uranium at first because it has been used 
before in such experiments. Under the tremendous impact of the atomic 
bullets, atoms of this element will be shattered. Great clouds of slow neu- 
trons will be released. With their power to destroy they will blast more 
atoms of the element, releasing more neutrons to impact on and shatter 
more atoms. With each of these shattering blows energy in excess of 175,- 
000,000 volts will be released. Thus will be achieved the "chain reaction," 
or chain of atomic explosions, that has been hoped for and which should 
be attainable with the 4900-ton cyclotron. 

When I went to see Dr. Lawrence, I was a bit worried about what 
might happen when this chain reaction started. After all, there would be 
an almost unbelievable amount of energy released. What if they couldn't 
stop the reaction and it just kept going on releasing more and more 
energy? There might be a terrific outburst that would send cyclotron, 
Nobel prize winner and everything else sailing up into the sky. But when 
I broached this question, Dr. Lawrence just smiled and said, "Well, that's 
not really such a great danger because the neutron's own properties will 
protect us from such an eventuality. You see, the slow neutron has great 
disintegrating power. We'll use this power to release the sub-atomic 
energy. But as the explosions continue, the element we are breaking up 
will become white hot. As the temperature rises, the neutrons will streak 


along at a constantly faster pace. As you know, a neutron loses in disinte- 
grating power and gains in penetrating power as it speeds up. Pretty soon 
all these neutrons released will be just passing through the atoms without 
destroying them and the reaction will come to a natural conclusion. But 
by that time we'll already have obtained enough energy to last us a good 
long while." 


The Discovery of Radium 


From Madame Curie 

baby daughter and put pans on the fire, in a wretched laboratory 
at the School of Physics a woman physicist was making the most impor- 
tant discovery of modern science. 

At the end of 1897 the balance sheet of Marie's activity showed two 
university degrees, a fellowship and a monograph on the magnetization 
of tempered steel. No sooner had she recovered from childbirth than she 
was back again at the laboratory. 

The next stage in the logical development of her career was the doctor's 
degree. Several weeks of indecision came in here. She had to choose a 
subject of research which would furnish fertile and original material. Like 
a writer who hesitates and asks himself questions before settling the sub- 
ject of his next novel, Marie, reviewing the most recent work in physics 
with Pierre, was in search of a subject for a thesis. 

At this critical moment Pierre's advice had an importance which can- 
not be neglected. With respect to her husband, the young woman regarded 
herself as an apprentice: he was an older physicist, much more experi- 
enced than she. He was even, to put it exactly, her chief, her "boss." 


But without a doubt Marie's character, her intimate nature, had a great 
part in this all-important choice. From childhood the Polish girl had car- 
ried the curiosity and daring of an explorer within her. This was the in- 
stinct that had driven her to leave Warsaw for Paris and the Sorbonne, 
and had made her prefer a solitary room in the Latin Quarter to the 
Dluskis' downy nest. In her walks in the woods she always chose the 
wild trail or the unfrequented road. 

At this moment she was like a traveler musing on a long voyage. Bent 
over the globe and pointing out, in some far country, a strange name that 
excites his imagination, the traveler suddenly decides to go there and no- 
where else: so Marie, going through the reports of the latest experimental 
studies, was attracted by the publication of the French scientist Henri Bec- 
querel of the preceding year. She and Pierre already knew this work; she 
read it over again and studied it with her usual care. 

After Roentgen's discovery of X rays, Henri Poincare conceived the 
idea of determining whether rays like the X ray were emitted by "flu- 
orescent" bodies under the action of light. Attracted by the same problem, 
Henri Becquerel examined the salts of a "rare metal," uranium. Instead 
of finding the phenomenon he had expected, he observed another, alto- 
gether different and incomprehensible : he found that uranium salts spon- 
taneously emitted, without exposure to light, some rays of unknown na 
ture. A compound of uranium, placed on a photographic plate surrounded 
by black paper, made an impression on the plate through the paper. And, 
like the X ray, these astonishing "uranic" salts discharged an electroscope 
by rendering the surrounding air a conductor. 

Henri Becquerel made sure that these surprising properties were not 
caused by a preliminary exposure to the sun and that they persisted when 
the uranium compound had been maintained in darkness for several 
months. For the first time, a physicist had observed the phenomenon to 
which Marie Curie was later to give the name of radioactivity. But the 
nature of the radiation and its origin remained an enigma. 

Becquerel's discovery fascinated the Curies. They asked themselves 
whence came the energy tiny, to be sure which uranium compounds 
constantly disengaged in the form of radiation. And what was the nature 
of this radiation? Here was an engrossing subject of research, a doctor's 
thesis! The subject tempted Marie most because it was a virgin field: 
Becquerel's work was very recent and so far as she knew nobody in the 
laboratories of Europe had yet attempted to make a fundamental study 
of uranium rays. As a point of departure, and as the only bibliography, 
there existed some communications presented by Henri Becquerel at the 


Academy of Science during the year 1896. It was a leap into great adven- 
ture, into an unknown realm. 

There remained the question o where she was to make her experi- 
ments and here the difficulties began. Pierre made several approaches to 
the director of the School of Physics with practically no results: Marie was 
given the free use of a little glassed-in studio on the ground floor of the 
school. It was a kind of storeroom, sweating with damp, where unused 
machines and lumber were put away. Its technical equipment was rudi- 
mentary and its comfort nil. 

Deprived of an adequate electrical installation and of everything that 
forms material for the beginning of scientific research, she kept her pa- 
tience, sought and found a means of making her apparatus work in this 

It was not easy. Instruments of precision have sneaking enemies: humid- 
ity, changes of temperature. Incidentally the climate of this little work- 
room, fatal to the sensitive electrometer, was not much better for Marie's 
health. But this had no importance. When she was cold, the young woman 
took her revenge by noting the degrees of temperature in centigrade in 
her notebook. On February 6, 1898, we find, among the formulas and 
figures: "Temperature here 6 '25. [About 44 Fahrenheit.] Six de- 
grees . . . !" Marie, to show her disapproval, added ten little exclamation 

The candidate for the doctor's degree set her first task to be the measure- 
ment of the "power of ionization" of uranium rays that is to say, their 
power to render the air a conductor of electricity and so to discharge an 
electroscope. The excellent method she used, which was to be the key to 
the success of her experiments, had been invented for the study of other 
phenomena by two physicists well known to her: Pierre and Jacques 
Curie. Her technical installation consisted of an "ionization chamber," a 
Curie electrometer and a piezoelectric quartz. 

At the end of several weeks the first result appeared: Marie acquired 
the certainty that the intensity of this surprising radiation was propor- 
tional to the quantity of uranium contained in the samples under exam- 
ination, and that this radiation, which could be measured with precision, 
was not affected either by the chemical state of combination of the ura- 
nium or by external factors such as lighting or temperature. 

These observations were perhaps not very sensational to the uninitiated, 
but they were of passionate interest to the scientist. It often happens in 
physics that an inexplicable phenomenon can be subjected, after some in- 
vestigation, to laws already known, and by this very fact loses its interest 
for the research worker. Thus, in a badly constructed detective story, if we 


are told in the third chapter that the woman of sinister appearance who 
might have committed the crime is in reality only an honest little house- 
wife who leads a life without secrets, we feel discouraged and cease to 

Nothing of the kind happened here. The more Marie penetrated into 
intimacy with uranium rays, the more they seemed without precedent, 
essentially unknown. They were like nothing else. Nothing affected them. 
In spite of their very feeble power, they had an extraordinary individuality. 

Turning this mystery over and over in her head, and pointing toward 
the truth, Marie felt and could soon affirm that the incomprehensible 
radiation was an atomic property. She questioned: Even though the phe- 
nomenon had only been observed with uranium, nothing proved that 
uranium was the only chemical element capable of emitting such radia- 
tion. Why should not other bodies possess the same power? Perhaps it 
was only by chance that this radiation had been observed in uranium first, 
and had remained attached to uranium in the minds of physicists. Now it 
must be sought for elsewhere. . . . 

No sooner said than done. Abandoning the study of uranium, Marie 
undertook to examine all \nown chemical bodies, either in the pure state 
or in compounds. And the result was not long in appearing: compounds 
of another element, thorium, also emitted spontaneous rays like those of 
uranium and of similar intensity. The physicist had been right: the sur- 
prising phenomenon was by no means the property of uranium alone, and 
it became necessary to give it a distinct name. Mme Curie suggested the 
name of radioactivity. Chemical substances like uranium and thorium, 
endowed with this particular "radiance," were called radio elements. 

Radioactivity so fascinated the young scientist that she never tired of 
examining the most diverse forms of matter, always by the same method. 
Curiosity, a marvelous feminine curiosity, the first virtue of a scientist, 
was developed in Marie to the highest degree. Instead of limiting her ob- 
servation to simple compounds, salts and oxides, she had the desire to 
assemble samples of minerals from the collection at the School of Physics, 
and of making them undergo almost at hazard, for her own amusement, 
a kind of customs inspection which is an electrometer test. Pierre ap- 
proved, and chose with her the veined fragments, hard or crumbly, oddly 
shaped, which she wanted to examine. 

Marie's idea was simple simple as the stroke of genius. At the cross- 
roads where Marie now stood, hundreds of research workers might have 
remained, nonplussed, for months or even years. After examining all 
known chemical substances, and discovering as Marie had done the 
radiation of thorium, they would have continued to ask themselves in 


vain whence came this mysterious radioactivity. Marie, too, questioned 
and wondered. But her surprise was translated into fruitful acts. She had 
used up all evident possibilities. Now she turned toward the unplumbed 
and the unknown. 

She knew in advance what she would learn from an examination of 
the minerals, or rather she thought she knew. The specimens which con- 
tained neither uranium nor thorium would be revealed as totally "inac- 
tive." The others, containing uranium or thorium, would be radioactive. 

Experiment confirmed this prevision. Rejecting the inactive minerals, 
Marie applied herself to the others and measured their radioactivity. Then 
came a dramatic revelation: the radioactivity was a great deal stronger 
than could have been normally foreseen by the quantity of uranium or 
thorium contained in the products examined! 

"It must be an error in experiment," the young woman thought; for 
doubt is the scientist's first response to an unexpected phenomenon. 

She started her measurements over again, unmoved, using the same 
products. She started over again ten times, twenty times. And she was 
forced to yield to the evidence: the quantities of uranium found in these 
minerals were by no means sufficient to justify the exceptional intensity 
of the radiation she observed. 

Where did this excessive and abnormal radiation come from? Only 
one explanation was possible: the minerals must contain, in small quan- 
tity, a much more powerfully radioactive substance than uranium and 

But what substance? In her preceding experiments, Marie had already 
examined all \nown chemical elements. 

The scientist replied to the question with the sure logic and the mag- 
nificent audaciousness of a great mind: The mineral certainly contained 
a radioactive substance, which was at the same time a chemical element 
unknown until this day: a new element. 

A new element! It was a fascinating and alluring hypothesis but still 
a hypothesis. For the moment this powerfully radioactive substance existed 
only in the imagination of Marie and of Pierre. But it did exist there. It 
existed strongly enough to make the young woman go to see Bronya one 
day and tell her in a restrained, ardent voice: 

"You know, Bronya, the radiation that I couldn't explain comes from 
a new chemical element. The element is there and I've got to find it. We 
are sure! The physicists we have spoken to believe we have made an error 
in experiment and advise us to be careful. But I am convinced that I am 
not mistaken." 


These were unique moments in her unique life. The layman forms a 
theatrical and wholly false idea of the research worker and of his dis- 
coveries. "The moment of discovery" does not always exist: the scientist's 
work is too tenuous, too divided, for the certainty of success to crackle out 
suddenly in the midst of his laborious toil like a stroke of lightning, daz- 
zling him by its fire. Marie, standing in front of her apparatus, perhaps 
never experienced the sudden intoxication of triumph. This intoxication 
was spread over several days of decisive labor, made feverish by a mag- 
nificent hope. But it must have been an exultant moment when, convinced 
by the rigorous reasoning of her brain that she was on the trail of new 
matter, she confided the secret to her elder sister, her ally always. . . . 
Without exchanging one affectionate word, the two sisters must have lived 
again, in a dizzying breath of memory, their years of waiting, their mutual 
sacrifices, their bleak lives as students, full of hope and faith. 

It was barely four years before that Marie had written: 

Life is not easy for any of us. But what of that? We must have persever- 
ance and above all confidence in ourselves. We must believe that we are 
gifted for something, and that this thing, at whatever cost, must be attained. 

That "something" was to throw science upon a path hitherto unsus- 

In a first communication to the Academy, presented by Prof. Lipp- 
mann and published in the Proceedings on April 12, 1898, "Marie Sklodov- 
ska Curie" announced the probable presence in pitchblende ores of a new 
element endowed with powerful radioactivity. This was the first stage of 
the discovery of radium. 

By the force of her own intuition the physicist had shown to herself 
that the wonderful substance must exist. She decreed its existence. But its 
incognito still had to be broken. Now she would have to verify hypothesis 
by experiment, isolate this material and see it. She must be able to 
announce with certainty: "It is there." 

Pierre Curie had followed the rapid progress of his wife's experiments 
with passionate interest. Without directly taking part in Marie's work, he 
had frequently helped her by his remarks and advice. In view of the 
stupefying character of her results, he did not hesitate to abandon his study 
of crystals for the time being in order to join his efforts to hers in the search 
for the new substance. 

Thus, when the immensity of a pressing task suggested and exacted 
collaboration, a great physicist was at Marie's side a physicist who was 
the companion of her life. Three years earlier, love had joined this excep- 


tional man and woman together love, and perhaps some mysterious fore- 
knowledge, some sublime instinct for the work in common. 

The valuable force was now doubled. Two brains, four hands, now 
sought the unknown element in the damp little workroom in the Rue 
Lhomond. From this moment onward it is impossible to distinguish each 
one's part in the work of the Curies. We know that Marie, having chosen 
to study the radiation of uranium as the subject of her thesis, discovered 
that other substances were also radioactive. We know that after the ex- 
amination of minerals she was able to announce the existence of a new 
chemical element, powerfully radioactive, and that it was the capital im- 
portance of this result which decided Pierre Curie to interrupt his very 
different research in order to try to isolate this element with his wife. At 
that time May or June, 1898 a collaboration began which was to last 
for eight years, until it was destroyed by a fatal accident. 

We cannot and must not attempt to find out what should be credited to 
Marie and what to Pierre during these eight years. It would be exactly 
what the husband and wife did not want. The personal genius of Pierre 
Curie is known to us by the original work he had accomplished before this 
collaboration. His wife's genius appears to us in the first intuition of dis- 
covery, the brilliant start; and it was to reappear to us again, solitary, when 
Marie Curie the widow unflinchingly carried the weight of a new science 
and conducted it, through research, step by step, to its harmonious ex- 
pansion. We therefore have formal proof that in the fusion of their two 
efforts, in this superior alliance of man and woman, the exchange was 

Let this certainly suffice for our curiosity and admiration. Let us not 
attempt to separate these creatures full of love, whose handwriting alter- 
nates and combines in the working notebooks covered with formulae, 
these creatures who were to sign nearly all their scientific publications to- 
gether. They were to write "We found" and "We observed"; and when 
they were constrained by fact to distinguish between their parts, they were 
to employ this moving locution : 

Certain minerals containing uranium and thorium (pitchblende, chal- 
colite, uranite) are very active from the point of view of the emission of 
Becquerel rays. In a preceding communication, one of us showed that their 
activity was even greater than that of uranium and thorium, and stated the 
opinion that this effect was due to some other very active substance contained 
in small quantity in these minerals. 

(Pierre and Marie Curie: Proceedings of the Academy of Science, July 18, 


Marie and Pierre looked for this "very active" substance in an ore of 
uranium called pitchblende, which in the crude state had shown itself to 
be four times more radioactive than the pure oxide of uranium that could 
be extracted from it. But the composition of this ore had been known for 
a long time with considerable precision. The new element must therefore 
be present in very small quantity or it would not have escaped the notice 
of scientists and their chemical analysis. 

According to their calculations "pessimistic" calculations, like those 
of true physicists, who always take the less attractive of two probabilities 
the collaborators thought the ore should contain the new element to a 
maximum quantity of one per cent. They decided that this was very little. 
They would have been in consternation if they had known that the radio- 
active element they were hunting down did not count for more than a 
millionth part of pitchblende ore. 

They began their prospecting patiently, using a method of chemical 
research invented by themselves, based on radioactivity; they separated all 
the elements in pitchblende by ordinary chemical analysis and then 
measured the radioactivity of each of the bodies thus obtained. By suc- 
cessive eliminations they saw the "abnormal" radioactivity take refuge in 
certain parts of the ore. As they went on, the field of investigation was 
narrowed. It was exactly the technique used by the police when they 
search the houses of a neighborhood, one by one, to isolate and arrest a 

But there was more than one malefactor here: the radioactivity was 
concentrated principally in two different chemical fractions of the pitch- 
blende. For M. and Mme Curie it indicated the existence of two new ele- 
ments instead of one. By July 1898 they were able to announce the dis- 
covery of one of these substances with certainty. 

"You will have to name it," Pierre said to his young wife, in the same 
tone as if it were a question of choosing a name for little Irene. 

The one-time Mile Sklodovska reflected in silence for a moment. Then, 
her heart turning toward her own country which had been erased from the 
map of the world, she wondered vaguely if the scientific event would be 
published in Russia, Germany and Austria the oppressor countries and 
answered timidly : 

"Could we call it 'polonium'?" 

In the Proceedings of the Academy for July 1898 we read: 

We believe the substance we have extracted from pitchblende contains a 
metal not yet observed, related to bismuth by its analytical properties. If the 
existence of this new metal is confirmed we propose to call it polonium, 
from the name of the original country of one of us. 


The choice of this name proves that in becoming a Frenchwoman and 
a physicist Marie had not disowned her former enthusiasms. Another 
thing proves it for us : even before the note "On a New Radioactive Sub- 
stance Contained in Pitchblende" had appeared in the Proceedings of the 
Academy, Marie had sent the manuscript to her native country, to that 
Joseph Boguski who directed the little laboratory at the Museum of In- 
dustry and Agriculture where she had made her first experiments. The 
communication was published in Warsaw in a monthly photographic 
review called Swiatlo almost as soon as in Paris. . . . 

We find another note worthy of remark. 

It was drawn up by Marie and Pierre Curie and a collaborator called 
G. Bemont. Intended for the Academy of Science, and published in the 
Proceedings of the session of December 26, 1898, it announced the existence 
of a second new chemical element in pitchblende. 

Some lines of this communication read as follows: 

The various reasons we have just enumerated lead us to believe that the 
new radioactive substance contains a new element to which we propose to 
give the name of RADIUM. 

The new radioactive substance certainly contains a very strong proportion 
of barium; in spite of that its radioactivity is considerable. The radioactivity 
of radium therefore must be enormous. 

The Taming of Energy 


From Atoms in Action 

June day or a day in December, enough energy fell on the earth 
during that twenty-four hours to serve humanity for several centuries 
enough to keep the world's furnaces roasting and its refrigerators icy, to 
spin its wheels and refine its ores, and to fill for several hundred years every 
other present need for power. The wheels of civilization are kept turning 
by energy; and all this energy, whether we draw it from a gallon of gaso- 
line, a ton of coal, or a pound of butter, has come to us from the sun. 

So long as the sun keeps shining we appear to have little cause to worry 
about running out of energy, and the best evidence indicates that our pow- 
erhouse in the heavens will still be glowing brilliantly a billion years from 
now. Unfortunately, however, most of the energy we are now using came 
from the sun in ages past, and we are drawing heavily on the earth's sav- 
ings account of coal and oil instead of using our current energy income. 
Even though the sun sends us two hundred thousand times as much power 
as we use, most of this slips through our fingers, because we have not yet 
learned how to convert sunlight efficiently into those forms of energy 
which are useful for civilized living. 

Select on a map any convenient desert, and look at an area twenty miles 
square an area which would about cover the sprawling environs of a 
great city. Year after year enough sunlight is lavished on this small sandy 
waste to satisfy perpetually the power needs of the entire population of the 
United States at the present rate of power consumption. In fact, grimy 
miners digging six thousand tons of coal from the gloomy depths of the 
earth obtain only an amount of energy equivalent to that swallowed on a 
sunny day by a single square mile of land or sea. 

Almost every material problem of living turns out in the last analysis 
to be a problem of the control of energy. The householder, when he has 



paid his bills for fuel and electricity, is likely to consider that he has taken 
care of his energy requirements for the month, yet each bill from the gro- 
cer or the milliner is quite as truly a bill for energy. We do not buy a bas- 
ket of strawberries for the carbon, oxygen, and nitrogen atoms they con- 
tain, but for the energy stored by these atoms when they join together in 
molecules to form sugars, starches, flavors, and vitamines. That part of the 
cost of a lady's hat which does not represent business acumen on the part 
of the milliner is for stored and directed energy the atoms of matter of 
which the hat is composed are permanent, and will still exist when the hat 
has been discarded and burned. Only energy and knowledge of how to 
apply it are needed to re-create a hat from its smoke and ashes! 

Even such materials as gold, silver, and copper represent true wealth 
only as they represent the energy required to find, collect, and purify these 
metals. Our supply of matter on earth is not changing appreciably, for 
although a little hydrogen and helium leak off from the top of the atmos- 
phere, far more matter than we lose in this way is brought to the earth by 
meteorites. Iron may rust or be scattered, but it cannot be lost so long as 
sufficient energy remains to reconcentrate and re-refine it. Many a mine 
long abandoned as worthless has brought in a fortune when cheaper power 
or a more efficient concentrating process has made worth while the recov- 
ery of further metal from its scrap-heap. Only energy is needed to gather 
as much of every material as we may need from the air, the land, or the 

Energy is wealth, and in the case of apprenticed sunlight, wealth of a 
particularly desirable kind, for it is freshly created and does not involve 
robbing the poor, taxing the rich, or despoiling the earth of materials which 
may be needed by our descendants as much as by ourselves. Yet this energy 
is free to him who can discover how to capture and control it. 

The scientist who is most concerned with the investigation and control 
of energy is the physicist. In his researches on energy the physicist works 
very closely with the chemist, who is interested primarily in matter. Matter 
and energy are always closely related; and physics and chemistry, orig- 
inally a single science called natural philosophy, can never be separated 
completely, for they are the twin sciences which deal with the fundamental 
structure of our physical universe. 

The chemist gathers the minerals and fibers and oils which he finds in 
nature, reduces them to the elementary atoms of which they are composed, 
and then causes these atoms to recombine into thousands of new kinds of 


molecules, thus forming new perfumes and dyes, new flavors and fabrics 
and drugs. 

The physicist, however, takes apart the very atoms themselves, sending 
through wires the electrons which he thus collects, and operating with 
them his telephones and X-ray tubes and television outfits. Or he may 
induce the atoms to emit light rays of strange new colors, rays which he 
bends with lenses cleverly designed to enable him to discern objects which 
are too dark or small or transparent otherwise to be seen. 

As the physicist has gradually learned to control the grosser forms of 
energy such as heat and sound, he has been led to probe deeper and deeper 
into nature in studying the behavior of energy in its finer and more subtle 
forms, such as light and electricity and magnetism. He has now succeeded 
in penetrating down through the atom into its tiny nucleus or core, and 
one of his principal interests at the moment (though by no means the only 
one, nor necessarily the most important one) is to take sample atom cores 
apart to see what they are made of and how they are put together. The 
atom is being taken to pieces quite literally, for when one of the modern 
"atom-smashing" devices is put into operation the atomic debris comes 
flying out like dirt from a gopher hole in which a very industrious puppy 
is scratching. 

The scientist who appears preoccupied with the center of the atom is 
burrowing after the key to the structure of matter and energy, not because 
he expects to tap the energy in the atom, but because he knows that before 
nature can be controlled she must be understood. The physicist who is 
engaged in "pure" or fundamental research is attempting to understand 
nature. The applied physicist is attempting to control nature. The two 
kinds of investigators try to keep in close collaboration, but physics is a vast 
science which ranges from such theoretical subjects as Relativity to such 
practical applications as the phonograph, as the interests of its workers 
have ranged from those of Einstein to those of Edison. 

. . . "Atom smashing" (using the term broadly to cover fundamental 
research into the structure of matter and energy) pays astonishing divi- 
dends not a mere five per cent, nor one hundred per cent, but hundiyds 
of times the original investment. This is not fanciful romanticism, but 
stark bookkeeping which realistic corporations, headed by typical American 
business men, have many times demonstrated to their stockholders. 

The scientist, like the artist, creates something new merely by rearrange- 
ment of the old. An industry that gets its profits from digging coal or 
pumping oil or felling timber is constantly depleting its resources. An 
industry that rests on a physical discovery gets its profits through fresh 


Since wealth consists ultimately of the control of matter and energy, the 
wealth level of mankind slowly rises as science learns to capture a con- 
stantly growing fraction of the energy that is available and turn it more 
effectively to useful ends. A factory worker in the United States is paid 
several times as much in real wages as his predecessor received a generation 
ago. While management may justly claim credit for this improvement, it 
was made possible only by utilizing technological achievements resting on 
scientific discoveries, which made the labor of each worker more produc- 
tive. For the wages he received for one hour of labor in the middle 1930*5 
a factory worker in Italy could buy a certain amount of food, a similar 
worker in Great Britain could buy twice as much, but a worker in the 
United States could buy four times as much. Economists agree that tech- 
nological development and scientific discovery have been responsible for 
this higher level of plenty in the United States. Science is a great agency 
for social betterment, for the victories over nature which result from its 
application make possible increased wages and profits and reduced prices 
at the same time. 

Experience has shown no better way of eliminating poverty than by well- 
directed "atom smashing." Poverty can best be abolished by replacing it 
with wealth; and the systematic investigation of matter and energy without 
regard to immediate practical ends has turned out to be the most direct 
road to social riches. In the long run digging for truth has always proved 
not only more interesting, but more profitable, than digging for gold. If 
urged on by the love of digging, one digs deeper than if searching for some 
particular nugget. Practicality is inevitably short-sighted, and is self-handi- 
capped by the fact that it is looking so hard for some single objective that 
it may miss much that nature presents to one who is purposefully digging 
for whatever may turn up. 

Each dweller in the United States is now served, on the average, by 
energy equivalent to that which could be provided by thirty slaves such as 
sweated at the command of an ancient Egyptian king. In making this 
much energy available, science has contributed only a small fraction of 
what it can contribute. Human beings can be made at least twenty thou- 
sand times as wealthy as they are today; but only the fundamental inves- 
tigation of nature, such as is involved in "atom smashing," will show how. 


Energy can neither be created nor destroyed (except as it can be changed 
into matter under certain extreme conditions, and produced from 
matter), but it can appear in any of a dozen or more forms. If the physicist 
succeeds in backing a bit of energy into a corner, so to speak, he usually 


expects il to disappear like a witch in a fairy tale, and to reappear in an 
entirely different form. By careful study of many typical situations he has 
learned where to lie in wait for the reappearance of the energy so that he 
can pounce on it in its new guise, or, if it stay hidden, ferret out its place 
of concealment. All of our most useful machines, such as electric motors 
and kitchen ranges and cameras, are merely clever devices for beguiling 
energy of one form into changing itself into another form which we desire 
to use. By touching a match to a gallon of gasoline we can cause the 
chemical energy which the gasoline contains to be transformed into thermal 
energy; but if instead we use a spark plug in an automobile cylinder, much 
of the thermal energy, when it appears, will find itself harnessed to perform 
mechanical work. 

The most useful forms of energy for practical purposes are those we call 
heat, sound, and light, and the mechanical, electrical, magnetic, chemical, 
and gravitational forms. When we have learned how to convert energy 
from any one of these forms directly into any other at will, without letting 
much energy escape in the process, the millennium will have arrived so 
far as the cost of living is concerned. 

If, for example, we knew how to convert electrical energy directly into 
light, the problem of "cold light" would be solved. At present we must use 
indirect means, as in the incandescent lamp, where electrical energy is 
forced to heat a tungsten filament and thus is turned into heat energy. 
When heat has set the filament glowing some of its energy is transformed 
into useful light as a by-product, but nine-tenths of the energy is wasted as 
invisible radiation, boosting our electric light bills to ten times what they 
should be. 

An example of the many useful applications which often result from the 
discovery of a new way of transforming one form of energy into another 
is given by the piezo-electric crystal. The brothers Pierre and Paul Curie 
found in 1880 that sensitive crystals of certain types, such as quartz and 
Rochelle salt, shrink and swell when given electric shocks. Thus was dis- 
covered a new method of changing electrical energy into mechanical 
energy. The crystals were found also to generate electric charges on their 
surfaces when squeezed or stretched, so they could be used to convert 
mechanical energy back into the electrical form as well. The Curie brothers 
were academic physicists, interested chiefly in digging out facts (Pierre, 
with his wife Marie, later discovered radium), so they made no use of their 
discovery. It lay unapplied until 1917, when, during the World War, 
another physicist decided that crystals might be useful for detecting the 
sound waves given out by submarines. His work was so successful that it 
suggested further fields for investigation, and later we shall find piezo- 


electric crystals being used for such diverse purposes as keeping radio 
broadcasting stations tuned to the proper frequency, serving as micro- 
phones for changing sound waves into electrical waves, and forming 
wave-filters which keep separate more than two hundred telephone conver- 
sations passing simultaneously over the same pair of wires. These accom- 
plished crystals also make excellent phonograph pickups, can be used as 
telephone transmitters and receivers, and operate the most accurate clocks 
in the world, which tick 100,000 times a second. Again, by tickling such 
crystals electrically at high frequency they can be made to emit super- 
sounds, which are of value for cracking crude oil to increase its yield of 
gasoline, for precipitating smoke, for detecting icebergs or other obstruc- 
tions at sea, and even for speeding up the pickling of cucumbers I 

The delay of thirty-seven years in putting the piezo-electric crystal to 
work occurred because good methods of applying rapid electric shocks to 
the crystal were not available until the electronic vacuum tube was in- 
vented, which in turn waited on the discovery of the electron. Thus the 
application of one important discovery is often forced to await the birth 
of another. 

Man's physical developments involve special transformations of energy 
from one form to another as in telephony, where sound vibrations are 
changed into electrical vibrations, carried through space on waves or over 
wires, and then changed back into sound vibrations; or in television, where 
the same is done for visual images. But fundamental to all such processes 
is the transportation and storage of energy in bulk. 


Transporting energy from place to place keeps millions of men busy. 
Most energy is transported in one of three ways : in coal carried by ships 
or freight cars; in oil carried by ships, tank cars, or pumped through pipe 
lines; or sent over wires as electrical power. More than half our energy is 
carried in coal. Electrical power is more convenient to use than any other 
kind, but even when energy is ultimately to be delivered in electrical form 
it is cheapest at present to carry it locked in coal or oil for as much of its 
journey as possible. 

In the United States there are 110,000 miles of pipes through which black 
oil flows, sometimes for more than a thousand miles on a single journey; 
65,000 additional miles of pipe carry natural gas for fuel; and together 
these buried pipe lines form a transportation system almost three-quarters 
as long as all the railroad tracks of the country. About half as much energy 
as is carried by oil and gas flows through wires, carried by electric currents 


consisting of countless electrons sent swinging Irom one copper atom to 
the next. 

To carry energy to its user costs much more than to dig it out of the 
ground as coal or to scoop it up with turbine blades from a waterfall. 
Though a ton of coal costs less than four dollars at the mine, delivered to 
the ultimate user it may cost four times as much. Electrical energy delivered 
in the home now costs on the average five and a half cents a kilowatt hour, 
more than ten times its cost to produce in wholesale lots at a steam plant 
near a coal mine. There is great need for development of cheaper electrical 
methods of transmitting power. Standard engineering methods are begin- 
ning to be found insufficient new methods must be provided by applying 
physics anew. 

At present electric power cannot be piped economically farther than a 
few hundred miles unless expensive special equipment is used; only when 
a tremendous load of power can be sold is it economical to provide this 
equipment. The electrical engineer delivering his kilowatts is in much the 
situation of a small boy carrying home sugar from the grocery store in a 
paper sack with a hole in its bottom which lets the sugar trickle slowly 
away. Since the engineer cannot now afford to plug the hole, only those 
persons can afford to buy electrical sugar whose homes are within a few 
hundred miles of an electrical power store. 

It has long been known that the most efficient way to send power over 
wires of a given size is to keep the flow of electric current as low as possible, 
and make the voltage, or electrical pressure of the line, as great as possible, 
Engineers have a working rule which says that a power line should be 
operated at such a high voltage that 1000 volts-is provided for each mile the 
power is carried. Since 350,000 volts is about the economical upper limit 
of voltage practical on present power lines, this sets a 350-mile limit: 

In 1941 the longest power line stretched 270 miles from Boulder Dam to 
Los Angeles. To carry energy from such great water-power developments 
as Tennessee Valley to the large cities where power is most needed, 
methods of using higher voltages must "be provided. But raising the voltage 
of a standard power line above 350,000 volts may cause the bottom to drop 
out of the electrical sugar bag the air, the line, and the insulators refuse to 
co-operate longer in keeping the electrical flow intact. 

Long-distance transmission lines now operate with alternating current, 
briefly written A.C. Electricity is first pushed into one wire of* the line and 
pulled from the other, and then the push and pull are reversed. Pushes 
and pulls are usually alternated 120 times in a second, giving 6o-cycle A.C. 
Power can also be transmitted with direct current (D.-C.) by pumping 
electrons continuously into one wire*and out of the other, and it* is known 


that with such D.C. transmission much less electricity leaks from a line 
than with A.C. Short lines operating at more than a million volts D.C. 
have been used experimentally to carry power. However, the transformers 
which give the most convenient means of stepping electricity up from a 
low voltage to a high voltage, or stepping it down again, operate only 
with alternating current. For safety, power must be generated and used 
at low voltages; yet for economy it must be sent over a long line at high 
voltage. This combination of necessities sets a pretty dilemma. 

Here the electronic vacuum tube enters the picture; and with its aid the 
problem may well be solved. With tubes of one type direct current can be 
changed to alternating current at any voltage. By using tubes of a second 
type alternating current can be changed to direct. Such tubes should make 
it possible to generate alternating current power, step this up to high 
voltage with transformers, change the power to D.C. with a vacuum tube 
and send it over the long-distance power line, at the far end change it back 
to A.C. with another vacuum tube, and then step it down with a trans- 
former to the desired voltage for use. This process of sidestepping nature's 
obstacles, which might be described in football terms as a double lateral 
pass with a forward pass between, sounds complex, but actually it is simple 
once the vacuum tubes have been put into reliable working order.. A trial 
installation of this sort has been kept in satisfactory operation by the 
General Electric Company in Schenectady for several years. 

An entirely different attack on the problem of high-voltage D.C. power 
transmission has been suggested by the work of an atom-smashing 
physicist, Dr. Robert J. Van de Graaff, and his collaborators. They were 
interested, not so much in developing a new means of transmitting power, 
as in perfecting a high-voltage machine which would generate 5,000,000 
volts with which to hurl electrical bullets against the cores of atoms which 
were to be smashed. In Van de Graaff's generator, electrons are sprayed 
against wide rubber belts. To these belts the electrons stick, and by them 
are carried up into a large metal sphere, which they gradually charge with 
electricity. The sphere is carefully insulated from the ground by a sup- 
porting column thirty feet high, and so smooth and round is this sphere 
that electricity can leak into the air from it but slowly. If electrons are 
pumped indefinitely into the sphere its electrical pressure rises until finally 
a voltage is reached which the air can resist no longer, and a great flash of 
artificial lightning jumps between the sphere and any near-by object con- 
nected to the ground. With -such a generator several million volts might 
be applied directly to a power line, no transformers would be needed at the 
beginning of the line, and extremely weak direct currents would suffice 
to transmit large amounts of power with little loss. 


Scientists have envisaged long D.C. lines consisting of a pipe, buried in 
the earth with a wire stretched down its center, carrying power from great 
hydraulic turbo-generators, or from steam plants located near coal mines, 
to any city in the country. The pipe might be filled with carbon tetra- 
chloride vapor, or with the Freon vapor used in refrigerators, to reduce 
leakage of electricity between the wire and the pipe. It has even been sug- 
gested that the pipe might be evacuated over its whole length of more than 
a thousand miles, for electricity cannot leak across a well-evacuated space. 
To obtain a suitable vacuum thousands of high-speed pumps would have 
to be kept sucking on the pipe like piglets on a myriad-breasted mother 
pig. At present such a project is perhaps visionary, but it illustrates how 
the practicability of an engineering scheme may hinge on new develop- 
ments of physics in this case, on a high-voltage generator and a more 
efficient vacuum pump. 

Must wires always be used to carry electric power from place to place, 
or could rays be used instead? Dreamers have long talked of powerful 
rays which could be focused on distant machinery to which energy was 
thus supplied. Keeping airplanes aloft without fuel is a favorite applica- 
tion. At present no rays energetic enough for this purpose and at the same 
time available in quantity are known to scientists. Radio waves and light 
waves are more suited to such comparatively dainty tasks as carrying 
messages than to feeding engines with power. Machinery can be operated 
with the energy contained in rays of sunlight, to be sure, but the power 
these carry is insufficiently concentrated to be worth using at present, even 
when available. Rays of more concentrated types have either insufficient 
penetrating power to travel far through the air, or are uncontrollable, or 
are available only in very small quantities. Energy can be most readil) 
controlled by giving it matter to cling to when it is to be stored, concen- 
trated, or carried from place to place with little loss. 


To store energy for future use is much more difficult than to release 
energy already stored in matter. When fuel is burned, the chemical energy 
stored in it is released as heat energy; but the reverse process unburning 
a gallon of gasoline or a cord of wood is very slow and difficult. Nature 
unburns wood when she uses sunlight in plants to release carbon atoms 
from the carbon dioxide molecules which the leaf has picked up, wafted 
through the air from some long-forgotten fire. Man has not yet learned to 
imitate nature in this regard, though he is beginning to get some clues as 
to how the job is done. 

One can store energy mechanically, as by winding a clock or bending a 


bow; electrically, as by charging a condenser; gravitationally, as by pump- 
ing water into a high reservoir; thermally, as in a hot water bottle; chem- 
ically, as by charging a storage battery or growing a tree; and in many 
other ways. All involve associating energy with matter. 

In comparing storage processes a most important question is, How much 
energy can be packed into each pound of matter? We can get an idea of 
the energy-holding capacity of matter by seeing how much energy can be 
released from a pound of each of a number of fuels; this energy can readily 
be evaluated in terms of how long a pound of the fuel would keep a 
6o-watt incandescent lamp burning if all its energy were converted into 
electric power. Thus, a pound of wood would keep the lamp alight for 
about 200 hours, a pound of coal for twice as long, a pound of gasoline 
for 900 hours. Hydrogen is one of the best energy-storing substances obtain- 
able, for in a pound of this gas is stored enough energy to keep the lamp 
bright for nearly 2700 hours. 

Any method of producing such fuels is a method of storing energy in 
chemical form; and chemical storage, in which the energy is tucked 
between atoms when these are grouped together to form molecules, appears 
to be the best of any practical method now available to store energy with 
little weight. Even fuels are heavier energy-storage reservoirs than we 
would like, however; witness the concern of the aviator whose two tons 
of gasoline must carry him across the Atlantic Ocean. 

Any youth who wishes to win fame and fortune through scientific 
discovery, but who cannot think of anything which needs discovering, 
would do well to turn his attention to the problem of storing energy lightly. 
If he could invent a device into which electrical energy could be fed, which 
would store this energy chemically and later release it again as electrical 
energy, his fortune might be made if the device was light enough. Such a 
device is, of course, merely a storage battery; but all present storage bat- 
teries, though extremely efficient, are far too heavy to be used for anything 
but odd jobs such as starting automobiles. One pound of ordinary lead 
storage battery, when fully charged, holds less than one-twentieth as much 
energy as is contained in a pound of gasoline. 

If a storage battery weighing less than one-tenth as much as present bat- 
teries were to become available, the electric automobile would probably 
supersede the gasoline motor car almost immediately. What magic does 
the heavy lead atom, now used for almost all storage of electrical energy, 
possess which enables it to store energy and give this out again at the will 
of the user, which is not possessed by, say, the lithium or the beryllium 
atoms, weighing one-thirtieth as much ? There seems to be no reason for 
supposing that a light storage battery cannot be invented, except that many 


people have tried doing this, and no one has yet succeeded. Such argu- 
ments have, of course, never deterred resourceful men. To invent a light 
battery, the old method was to start by trying thousands of different light 
materials; the new method is carefully to study nature and find how she 
packs energy into atoms and molecules. 

Edition of 

Space, Time and Einstein* 


all heard of the Einstein theory, and failure to understand it does 
not seem incompatible with the holding of opinions on the subject, some- 
times of a militant and antagonistic character. 

Twenty-four years have elapsed since Einstein published his first paper 
on relativity, dealing principally with certain relations between mechanics 
and optics. Since that time a new generation has grown up to whom pre- 
Einstein science is a matter of history, not of experience. Eleven years 
after his first paper Einstein published a second, in which he broadened 
and extended the theory laid down in the first so as to include gravitation. 
And now again, thirteen years later, in a third paper, Einstein has 
broadened his theory still farther so as to include the phenomena of 
electricity and magnetism, 

In view of the rekindling of interest in Einstein because of the appear- 
ance of his latest paper it may be worth while to reexamine and restate 
the primary foundations upon which his theory rests. 

The general interest taken in this subject is frequendy a matter of 
wonder to those of us who must give it attention professionally, for there 

* Publication approved by the Director of the Bureau of Standards of the U. S. Depart- 
ment of Commerce. 


are in modern physical science other doctrines which run closely second 
to that of Einstein in strangeness and novelty, yet none o these seems to 
have taken any particular hold on popular imagination. 

Perhaps the reason for this is that these theories deal with ideas which 
are remote from ordinary life, while Einstein lays iconoclastic hands on 
two concepts about which every intelligent person believes that he really 
knows something space and time. 

Space and time have been regarded "always, everywhere and by all," 
as independent concepts, sharply distinguishable from one another, with 
no correlation between them. Space is fixed, though we may move about 
in it at will, forward or backward, up or down; and wherever we go our 
experience is that the properties of space are everywhere the same, and 
are unaltered whether we are moving or stationary. Time, on the other 
hand, is essentially a moving proposition, and we must perforce move 
with it. Except in memory, we can not go back in time; we must go 
forward, and at the rate at which time chooses to travel. We are on a 
moving platform, the mechanism of which is beyond our control. 

There is a difference also in our measures of space and time. Space may 
be measured in feet, square feet or cubic feet, as the case may be, but time 
is essentially one-dimensional. Square hours or cubic seconds are mean- 
ingless terms. Moreover, no connection has ever been recognized between 
space and time measures. How many feet make one hour? A meaningless 
question, you say, yet something that sounds very much like it has (since 
Minkowski) received the serious attention of many otherwise reputable 
scientific men. And now comes Einstein, rudely disturbing these old- 
established concepts and asking us to recast our ideas of space and time 
in a way that seems to us fantastic and bizarre. 

What has Einstein done to these fundamental concepts? 

He has introduced a correlation or connecting link between what have 
always been supposed to be separate and distinct ideas. In the first place, 
he asserts that as we move about, the geometrical properties of space, as 
evidenced by figures drawn in it, will alter by an amount depending on 
the speed of the observer's motion, thus (through the concept of velocity) 
linking space with time. He also asserts in the second place that the flow 
of time, always regarded as invariable, will likewise alter with the motion 
of the observer, again linking time with space. 

For example, suppose that we, with our instruments for measuring 
space and time, are located on a platform which we believe to be station- 
ary. We can not be altogether certain of this, for there is no other visible 
object in the universe save another similar platform carrying an observer 
likewise equipped : but when we observe relative motion between our plat- 


form and the other it pleases our intuition to suppose our platform at 
rest and to ascribe all the motion to the other. 

Einstein asserts that if this relative velocity were great enough we might 
notice some strange happenings on the other platform. True, a rather 
high velocity would be necessary, something comparable with the speed 
of light, say 100,000 miles a second; and it is tacitly assumed that we 
would be able to get a glimpse of the moving system as it flashed by. 
Granting this, what would we see? 

Einstein asserts that if there were a circle painted on the moving plat- 
form it would appear to us as an ellipse with its short diameter in the 
direction of its motion. The amount of this shortening would depend 
upon the speed with which the system is moving, being quite imper- 
ceptible at ordinary speeds. In the limit, as the speed approached that of 
light, the circle would flatten completely into a straight line its diameter 
perpendicular to the direction of motion. 

Of this shortening, says Einstein, the moving observer will be uncon- 
scious, for not only is the circle flattened in the direction of motion, but 
the platform itself and all it carries (including the observer) share in 
this shortening. Even the observer's measuring rod is not exempt. Laid 
along that diameter of the circle which is perpendicular to the line of 
motion it would indicate, say, ten centimeters; placed along the shortened 
diameter, the rod, being itself now shortened in the same ratio, would 
apparently indicate the same length as before, and the moving observer 
would have no suspicion of what we might be seeing. In fact, he might 
with equal right suppose himself stationary and lay all the motion to the 
account of our platform. And if we had a circle painted on our floor it 
would appear flattened to him, though not to us. 

Again, the clock on the other observer's platform would exhibit to us, 
though not to him, an equally eccentric behavior. Suppose that other 
platform stopped opposite us long enough for a comparison of clocks, and 
then, backing off to get a start, flashed by us at a high speed. As it passed 
we would see that the other clock was apparently slow as compared with 
ours, but of this the moving observer would be unconscious. 

But could he not observe our clock ? 

Certainly, just as easily as we could see his. 

And would he not see that our clock was now faster than his? "No," 
says Einstein. "On the contrary, he would take it to be slower." 

Here is a paradox indeed! A's clock appears slow to B while at the 
same time B's clock appears slow to A\ Which is right? 

To this question Einstein answers indifferently: 

"Either. It all depends on the point of view." 


In asserting that the rate of a moving clock is altered by its motion 
Einstein has not in mind anything so materialistic as the motion inter- 
fering with the proper functioning of the pendulum or balance wheel. 
It is something deeper and more abstruse than that. He means that the 
flow of time itself is changed by the motion of the system, and that the 
clock is but fulfilling its natural function in keeping pace with the altered 
rate of time. 

A rather imperfect illustration may help at this point. If I were traveling 
by train from the Atlantic to the Pacific Coast it would be necessary for 
me to set my watch back an hour occasionally. A less practical but 
mathematically more elegant plan would be to alter the rate of my watch 
before starting so that it would indicate the correct local time during the 
whole journey. Of course, on a slow train less alteration would be 
required. The point is this: that a timepiece keeping local time on the 
train will of necessity run at a rate depending on the speed of the train. 

Einstein applies a somewhat similar concept to all moving systems, 
and asserts that the local time on such systems runs the more slowly the 
more rapidly the system moves. 

It is no wonder that assertions so revolutionary should encounter general 
incredulity. Skepticism is nature's armor against foolishness. But there 
are two reactions possible to assertions such as these. One may say: "The 
man is crazy" or one may ask: "What is the evidence?" 

The latter, of course, is the correct scientific attitude. To such a question 
Einstein might answer laconically: "Desperate diseases require desperate 

"But," we reply, "we are not conscious of any disease so desperate as 
to require such drastic treatment." 

"If you are not," says Einstein, "you should be. Does your memory run 
back thirty years? Or have you not read, at least, of the serious contra- 
diction in which theoretical physics found itself involved at the opening 
of the present century?" 

Einstein's reference is to the difficulty which arose as a consequence of 
the negative results of the famous Michelson-Morley experiment and 
other experiments of a similar nature. The situation that then arose is 
perhaps best explained by an analogy. 

If we were in a boat, stationary in still water, with trains of water- 
waves passing us, it would be possible to determine the speed of the 
waves by timing their passage over, say, the length of the boat. If the 
boat were then set in motion in the same direction in which the waves 
were traveling, the apparent speed of the waves with respect to the boat 
would be decreased, reaching zero when the boat attained the speed of 


the waves; and if the boat were set in motion in the opposite direction 
the apparent speed of the waves would be increased. 

If the boat were moving with uniform speed in a circular path, the 
apparent speed of the waves would fluctuate periodically, and from the 
magnitude of this fluctuation it would be possible to determine the speed 
of the boat. 

Now the earth is moving around the sun in a nearly circular orbit with 
a speed of about eighteen miles per second, and at all points in this orbit 
light waves from the stars are constantly streaming by. The analogy of 
the boat and the water-waves suggested to several physicists, toward the 
close of the nineteenth century, the possibility of verifying the earth's 
motion by experiments on the speed of light. 

True, the speed of the earth in its orbit is only one ten-thousandth of 
the speed of light, but methods were available of more than sufficient 
precision to pick up an effect of this order of magnitude. It was, there- 
fore, with the greatest surprise, not to say consternation, that the results 
of all such experiments were found to be negative; that analogy, for 
some unexplained reason, appeared to have broken down somewhere 
between mechanics and optics; that while the speed of water-waves varied 
as it should with the speed of the observer, the velocity of light seemed 
completely unaffected by such motion. 

Nor could any fault be found with method or technique. At least three 
independent lines of experiment, two optical and one electrical, led to the 
same negative conclusion. 

This breakdown of analogy between mechanics and optics introduced 
a sharp line of division into physical science. Now since the days of 
Newton the general trend of scientific thought has been in the direction 
of removing or effacing such sharp lines indicating differences in kind 
and replacing them by differences in degree. In other words, scientific 
thought is monistic, seeking one ultimate explanation for all phenomena. 

Kepler, by his study of the planets, had discovered the three well-known 
laws which their motion obeys. To him these laws were purely empirical, 
separate and distinct results of observation. It remained for Newton to 
show that these three laws were mathematical consequences of a single 
broader law that of gravitation. In this, Newton was a monistic 

The whole of the scientific development of the nineteenth century was 
monistic. Faraday and Oersted showed that electricity and magnetism 
were closely allied. Joule, Mayer and others pointed out the equivalence 
of heat and work. Maxwell correlated light with electricity and mag- 
netism. By the close of the century physical phenomena of all kinds were 


regarded as forming one vast, interrelated web, governed by some broad 
and far-reaching law as yet unknown, but whose discovery was confi- 
dently expected, perhaps in the near future. Gravitation alone obstinately 
resisted all attempts to coordinate it with othtx phenomena. 

The consequent reintroduction of a sharp line between mechanics and 
optics was therefore most disturbing. It was to remove this difficulty 
that Einstein found it necessary to alter our fundamental ideas regarding 
space and time. It is obvious that a varying velocity can be made to appear 
constant if our space and time units vary also in a proper manner, but 
in introducing such changes we must be careful not to cover up the 
changes in velocity readily observable in water-waves or sound waves. 

The determination of such changes in length and time units is a purely 
mathematical problem. The solution found by Einstein is what is known 
as the Lorentz transformation, so named because it was first found (in 
a simpler form) by Lorentz. Einstein arrived at a more general formula 
and, in addition, was not aware of Lorentz's work at the time of writing 
his own paper. 

The evidence submitted so far for Einstein's theory is purely retrospec- 
tive; the theory explains known facts and removes difficulties. But it must 
be remembered that this is just what the theory was built to do. It is a 
different matter when we apply it to facts unknown at the time the 
theory was constructed, and the supreme test is the ability of a theory to 
predict such new phenomena. 

This crucial test had been successfully met by the theory of relativity. 
In 1916 Einstein broadened his theory to include gravitation, which since 
the days of Newton had successfully resisted all attempts to bring it into 
line with other phenomena. From this extended theory Einstein predicted 
two previously unsuspected phenomena, a bending of light rays passing 
close by the sun and a shift of the Fraunhofer lines in the solar spectrum. 
Both these predictions have now been experimentally verified. 

Mathematically, Einstein's solution of our theoretical difficulties is 
perfect. Even the paradox of the two clocks, each appearing slower than 
the other, becomes a logical consequence of the Lorentz transformation. 
Einstein's explanation is sufficient, and up to the present time no one has 
been able to show that it is not necessary. 

Einstein himself is under no delusion on this point. He is reported to 
have said, "No amount of experimentation can ever prove me right; a 
single experiment may at any time prove me wrong." 

Early in the present year Einstein again broadened his theory to include 
the phenomena of electricity and magnetism. This does not mean that 
he has given an electromagnetic explanation of gravitation; many attempts 


of this kind have been made, and all have failed in the same respect to 
recognize that there is no screen for gravitation. What Einstein has done 
is something deeper and broader than that. He has succeeded in finding 
a formula which may assume two special forms according as a constant 
which it contains is or is not zero. In the latter case the formula gives 
us Maxwell's equations for an electromagnetic field; in the former, 
Einstein's equations for a gravitative field. . . . 

Einstein's aim from the first has been to bring order, not confusion; 
to exhibit all the laws of nature as special cases of one all-embracing 
law. In his monism he is unimpeachably orthodox. 

But there are other monistic philosophers besides scientific men. You 
will recall Tennyson's vision of 

One law, one element, 

And one far-off, divine event 

To which the whole creation moves. 


The Foundations of Chemical Industry 



by throwing one brightly colored ball after the other into the air, 
catching each in turn and throwing it up again until he has quite a 
number moving from hand to hand. The system which he keeps in motion 
has an orderly structure. He changes it by selecting balls of different colors, 
altering the course or the sequence of the balls, or by adding to or 
diminishing the number with which he plays. 

With this figure in mind let us use our imaginations. Before us we have 
an assemblage of hundreds of thousands of jugglers varying in their 
degree of accomplishment; some handle only one ball, others, more 
proficient, keep several in motion, and there are still others of an as- 
tounding dexterity who play with an hundred or more at once. The balls 
they handle are of ninety different colors and sizes. The jugglers do not 
keep still but move about at varying rates; those handling few and light 
balls move more quickly than those handling many or heavier ones. 
These dancers bump into each other and when they do so in certain 
cases they exchange some of the balls which they are handling or one 
juggler may take all of those handled by another, but in no case are the 
balls allowed to drop. 


Now imagine the moving group to become smaller and smaller until 
the jugglers cease to be visible to us, even when they dance under the 
highest power microscope. If someone who had not seen them were to 
come to you and say that he proposed undertaking the problem of finding 
out how the balls were moving and what were the rules of the exchanges 
made, and further that he proposed utilizing his knowledge to control 
what each minute juggler was doing, you would tell him that his task was 



hopeless. If the chemist had listened to such advice there would be 
no chemical industry and you would lose so much that you would not be 
living in the way you are. 

The jugglers are the electromagnetic forces of matter, the balls are the 
atoms, and each group in the hands of the juggler is a molecule of a 
substance. In reality, of course, instead of each molecule being represented 
by one unit we should multiply our jugglers by trillions and trillions. 


The chemist, without even seeing them, has learned to handle these 
least units of materials in such a way as to get the arrangements which 
are more useful from those less useful. This power he has acquired as the 
outcome of his life of research, his desire to understand, even though 
understanding brought him no material gain, but mere knowledge. 
Because of his patience and devotion he has built a number of industries; 
all have this in common they serve to rearrange atoms of molecules or 
to collect molecules of one kind for the service of man. 


The study of the substances of the earth's crust, of the air over and of 
the waters under earth, which has led us to our present knowledge of the 
electron, atom, and molecule, has been more adventurous than many a 
great journey made when the world was young and the frontier of the 
unknown was not remote from the city walls. Into the unknown world 
of things upon the "sea that ends not till the world's end" the man of 
science ventured, and he came back laden with treasure greater than all 
the gold and precious stones ever taken from the earth. He gave these to 
others and he fared forth again without waving of flags, without the 
benediction of holy church, with no more than the courage of him who 
would win Nature, who had chosen a harder road than that of the great, 
made famous because of subduing other men. He took no arms upon his 
quest, scarcely enough food to keep body and soul together, but instead, 
fire, glass, and that most astounding of all tools, the balance. As he pushed 
farther and farther on his great venture and as more and more joined his 
little band, he brought more and more back to those who did not under- 
stand in the least what he was doing, until now the lives of all men 
are made easier if not happier by these strange, most useful, and 
most potent things of which he is the creator by reason of the under- 
standing his journeys have given him a power much greater than 
any mere black magic. 


This is the story of some of the strange treasure found by him in the 
far lands that are about us treasure found by learning the secret of 
the jugglers' dance the dance of the least little things out of which all 
we know is fashioned. 


The Great Discovery 

In Sicily and other parts of the earth where there are volcanoes, lumps 
of a yellow crumbly "stone" are found, called brimstone (a corruption of 
brcnnisteinn or burning stone). This material was regarded as having 
curative properties; if it was burned in a house the bad odors of the 
sickroom of primitive times were suppressed. Also the alchemists found 
that it took away the metallic character of most metals and they con- 
sidered it very important in their search for the philosopher's stone, the 
talisman that was to turn all things to gold. The alchemists found also 
that sulfur, when burned over water, caused the water to become acid, and 
one of them found further that if the burning took place in the presence 
of saltpeter the acid which was produced was much stronger; indeed, if 
concentrated it was highly corrosive. A useless find, it seemed, of interest 
only to the alchemist who hoped to become rich beyond the dreams of 
avarice, and immortal as the gods. But the chemist made this discovery of 
more importance to the condition of the human race than that of Colum- 
bus, because by it he gave man a kingdom different from any that could 
have been his by merely discovering what already existed upon earth. 
That is the wonder of the chemist's work; he finds that which is not upon 
the earth until he discovers it; just as the artist creates so does the chemist. 
If he did not, there would be no chemical industry to write about. 

Experiment to Manufacture 

Having investigated this acid, he found it a most valuable new tool 
with which many new and interesting things could be made, and much 
could be done that before had been impossible. It became necessary, then, 
if all men were to profit as the chemist always wishes them to do by his 
power, that sulfuric acid should be made easily and cheaply in large 
quantities. The first attempt at commercial manufacture was in 1740; 
before that each experimenter made what little he needed for himself. 
The process, that mentioned above, was carried out in large glass bal- 
loons. It was a costly method and tedious. Then in 1746 lead chambers 
were substituted for the glass and the industry progressed rapidly. 


The whole object of this most basic of all chemical industries can be 
written in three simple little equations. 

Sulfur Oxygen Sulfur Dioxide 

S + O 2 = SO 2 

Sulfur Dioxide Oxygen Sulfur Trioxide 

50 2 + O 2 = SO 3 
Sulfur Trioxide Water Sulfuric Acid 

50 3 + H 2 = H 2 S0 4 

Of the three elements necessary, oxygen occurs uncombined in the 
air of which it forms one-fifth by volume; it is also present combined with 
other elements in very large quantities in water, sand, and generally 
throughout the earth's crust, which is nearly half oxygen in a com- 
bined condition. 

The Raw Materials 

The great storehouse of hydrogen on the earth is water, of which it 
forms one-ninth, by weight. Sulfur is not so widely distributed in large 
quantities but it is very prevalent, being present in all plants and animals 
and also in such compounds as Epsom salts, gypsum, and Glauber's salt. 
In the free condition, i.e., as sulfur itself, it is found in volcanic regions 
and also where bacteria have produced it by decomposing the products of 
plant decay. There is one other source of sulfur that is quite important, 
a compound with iron which contains so much sulfur that it will burn. 

The problem then was to take these substances and from them group 
the elements in such order as to produce sulfuric acid. 

Since sulfur burns readily, that is, unites with oxygen to form sulfur 
dioxide, one might expect it to take up one more atom of oxygen from the 
air and become sulfur trioxide. It does, but so slowly that the process 
would never suffice for commercial production. But there is a way of 
speeding up the reaction which depends on using another molecule as a 
go-between, thus making the oxygen more active. The principle is that 
of the relay. Suppose an out-fielder has to throw a ball a very long way. 
The chances are that the ball will not be very true and that it may fall 
short of reaching the base. If there is a fielder between, he can catch the 
ball and get it to the base with much greater energy. 

The chemist uses as a go-between a catalyst (in one process), oxides of 
nitrogen. Molecules of this gas throw an oxygen atom directly and un- 
failingly into any sulfur dioxide molecule they meet, then equally cer- 
tainly they seize the next oxygen atom that bumps into them and are 
ready for the next sulfur dioxide molecule. Since molecules in a gas 


mixture bump into each other roughly five billion times a second, there 
is a very good chance for the exchange to take place in the great lead 
chambers of approximately a capacity of 150,000 cubic feet into which are 
poured water molecules (steam), oxygen molecules (air), and sulfur 
dioxide, to which are added small quantities of the essential oxides o 

The Acid Rain 

A corrosive, sour drizzle falls to the floor and this is chamber acid. 
It is sold in a concentration of 70 to 80 per cent. The weak chamber acid 
is good enough for a great many industrial purposes and is very cheap. 
If it is to be concentrated this must be done in vessels of lead up to a 
certain concentration and then in platinum or gold-lined stills if stronger 
acid is needed. Naturally this is expensive and every effort was made to 
find a method of making strong sulfuric acid without the necessity of 
this intermediate step. Especially was this true when the dyestuffs 
industry began to demand very large quantities of tremendously strong 
sulfuric acid which was not only 100 per cent but also contained a con- 
siderable amount of sulfur trioxide dissolved in it (fuming sulfuric acid). 

The difficulty was overcome by using another catalyst (platinum) in 
the place of the oxides of nitrogen. If sulfur dioxide and oxygen (air) 
are passed over the metal the two gases unite to form sulfur trioxide much 
more rapidly and in the absence of water. Since platinum is very expensive 
and its action depends on the surface exposed, it is spread on asbestos 
fibers and does not look at all like the shiny metal of the jeweler. This 
method is known as the contact process and the product is sulfur tri- 
oxide, which represents the highest possible concentration of sulfuric acid 
and can be led into ordinary oil of vitriol (98 per cent sulfuric acid) and 
then diluted with water and brought to 98 per cent acid or left as fuming 
acid, depending on the requirements of the case. The perfection of this 
process was the result of some very painstaking research because when it 
was tried at first it was found that the platinum soon lost its virtue as a 
catalyst, and it was also discovered that the reason for this was the 
presence of arsenic in the sulfur dioxide. To get rid of every trace of 
arsenic is the hardest part of the contact process. 


Next time you visit a laboratory ask to be shown a bottle of concen- 
trated sulfuric acid. You will see a colorless, oily liquid, much heavier 
than water, as you will notice if you lift the bottle. A little on your skin 


will raise white weals and then dissolve your body right away; paper is 
charred by it as by fire. When it touches water there is a hissing. 

Sulfuric Acid and Civilization 

A dreadful oil, but its importance to industry is astonishing. If the art 
of making it were to be lost tomorrow we should be without steel and 
all other metals and products of the metallurgical industry; railroads, 
airplanes, automobiles, telephones, radios, reenforced concrete, all would 
go because the metals are taken from the earth by using dynamite made 
with sulfuric acid; and for the same reason construction work of all 
kinds, road and bridge building, canals, tunnels, and sanitary construction 
work would cease. 

We should have to find other ways to produce purified gasoline and 
lubricating oil. The textile industry would be crippled. We should find 
ourselves without accumulators, tin cans, galvanized iron, radio outfits, 
white paper, quick-acting phosphate fertilizers, celluloid, artificial leather, 
dyestuflfs, a great many medicines, and numberless other things into the 
making of which this acid enters at some stage. 

If at some future date, however, all of our sulfur and all of our sulfur 
ores are burned up the chemist will yet find ways of making sulfuric acid. 
Possibly he may tap the enormous deposits of gypsum which exist in all 
parts of the earth. This has been done to some extent already but is not 
a process which is cheap enough to compete with sulfuric acid made 
from sulfur. 


It is essential that all the heavy chemicals, that is, the most used acids, 
alkalies, and salts, should be made so far as possible from readily available 
cheap material. We use air, water, and abundant minerals on this account. 
Nitric acid caused the chemical industry much concern until it was found 
possible to make it from air, because until then its source was Chile 
saltpeter, or sodium nitrate, a mineral occurring in a quantity only in the 
arid Chilean highlands. However, this source of supply is still the most 
important and the process used is one of great interest. 

Having made oil of vitriol, the chemist found that he could produce 
other acids, one of the most important of these being liberated from salt- 
peter by the action of sulfuric acid. When nitric acid is made in this 
fashion we find that the sulfuric acid is changed into sodium sulfate and 
remains behind in the still. One might think from this that sulfuric acid 
is stronger and on that account that it drives out nitric acid, but in fact 


this preparation depends on a very simple principle, one of great 

Another Dance 

We may best illustrate it by returning to our former simile. Let us 
assume a sodium nitrate juggler moving rather slowly. He is bumped 
into by a sulfuric acid juggler moving at about the same rate. They 
exchange some of the atoms with which they are playing and in conse- 
quence one juggler holds sodium hydrogen sulfate while the other holds 
nitric acid. 

NaN0 3 + H 2 S0 4 - NaHSO 4 + HNO 3 

The nitric acid molecule does not slow down the juggler as much as 
the sodium hydrogen sulfate and therefore this particular dancer moves 
away quite fast. Suppose millions of these exchanges to be taking place; 
then the nitric acid molecules will continue to dance away and will not 
come back to exchange their atoms any more. If we keep them all in by 
putting a lid on, then they are forced to go back and we get no more 
than a sort of game of ball in which the hydrogen and sodium atoms are 
passed back and forth. If, on the other hand, we open the lid and put a 
fire under the pot, the nitric acid molecules move faster and sooner or 
later all of them are driven out. 

Nitric acid is now made from the air in more than one way so that 
we are entirely independent of the beds of Chile saltpeter no matter what 
might happen to them. Without nitric acid we could not make gun- 
cotton, dynamite, TNT, picric acid, ammonium nitrate, and the other 
explosives which are so enormously important to our civilization. In addi- 
tion, we would lose all our brilliant dyes and most of our artificial silk, 
from which it is easy to see that this substance is of great importance to 
all of us. 



Among the treasures to which man fell heir as the most important 
inhabitant of the earth was one of innumerable little cubes made of 
sodium and chloride, crystals of salt. These he noticed whenever seawater 
evaporated and he soon found, if he lived on a vegetable diet as he did in 
some places, that the addition of these to his food made it much more 
pleasant and savory. It fact, it is a necessity for the health of the human 
body, Hunting peoples do not use it so much because they live almost 


entirely on meat, which contains sufficient salt. Next it was found that 
salt could be employed for preserving fish and meat, and thus man was 
able to tide over the periods in which hunting was poor. For ages and 
ages it was put to no other use. Nobody but a chemist would have thought 
of doing anything with it. In order to understand the whole of what he 
did and the part which salt plays in industry owing to the chemist's 
activity we must go back a little. 

Soap as a Hair Dye 

Very early it was found that the ashes of a fire (and fires at that time 
were always made of wood) were useful in removing grease from the 
hands. They were the earliest form of soap and it is surprising how long 
they remained the only thing used. Our records go to show that the 
Romans were the first of the more civilized peoples to find out how to 
make real soap, and they learned it from the Gauls, who used the ma- 
terial which they made from wood ashes and goat's tallow for washing 
their hair and beards because they believed that this gave them the 
fiery red appearance which they thought was becoming. The Romans 
saw the advantage of soap over wood ashes and a very considerable trade 
in the making of various kinds of soaps arose, but the difficulty always 
was with the production of the ashes because it takes quite a lot of ashes 
to make even a small quantity of soap. The advantage of having some- 
thing more abundant to take the place of the ashes was evident. But 
the real stimulus which led to the discovery of soda ash came from a 
different source. 

Glass from Ashes and Sand 

It was found that ashes heated with sand formed glass. It was also 
found that the ashes of marine plants, or plants occurring on the seashore, 
gave a much better glass than that which could be made from the ashes 
of land plants. In consequence of this, as the art of glass making grew, 
barilla, the ashes of a plant growing in the salt marshes of Spain, became 
an increasingly important article of commerce and upon it depended the 
great glass factories of France and Bohemia. Owing to the political 
situation which arose at the end of the eighteenth century, France found 
herself in danger of losing her supremacy in the art of making glass 
because England cut off her supply of the Spanish ashes. For some reason 
the French ruler at the time had vision enough to see that it might 
be possible to make barilla artificially from some source within the 
kingdom of France and he offered a prize to any one who would make 
his country independent of Spain. We have seen that the chemist's busi- 


ness is the transmutation of one kind of material into another, and 
naturally it was the chemist who came forward with a solution of the 
problem. Since this process is now supplanted by a more economical one, 
we will merely outline it here. 

Limestone to Washing Soda 

Remember that it is essential to start from some abundant common 
material. Le Blanc, the chemist who solved the problem, knew that the 
Spanish ashes contained sodium carbonate, the formula of which we 
write as Na2COs; that is, it is a combination of sodium, carbon, and 
oxygen. There are a great many carbonates in nature and among these 
is that of calcium which we know as chalk, limestone, or marble, depend- 
ing on the way in which it crystallizes. In this we have a substance of the 
formula CaCOa. Suppose, then, we write the two compounds side by side: 
Na2COa, CaCOa. Evidently the only difference is that in one we have two 
atoms of sodium (Na2) in place of one of calcium (Ca) in the other. 
Salt contains sodium and is very common. If, then, we can get the sodium 
radical from the sodium chloride and the carbonate radical from the 
limestone and join the two pieces we will get sodium carbonate, which 
is what we want. What Le Blanc did was to treat sodium chloride with 
sulfuric acid. This gave him sodium sulphate and hydrochloric acid. Then 
he heated the sodium sulfate with coke or charcoal and limestone, after 
which he extracted the mass with water and found that he had sodium 
carbonate in solution. 

The steps do not sound difficult but it was really a great feat to 
make them commercially possible. In the first stage when sulfuric acid 
acted on the salt, hydrochloric acid was given off and this was a great 
nuisance. The amount of it produced exceeded any use that could be 
found for it and it was poured away; being highly acid it undermined 
the houses in the neighborhood and caused a great deal of trouble. Later, 
it became the most valuable product of the process because it was con- 
verted into bleaching powder by a method that we will take up subse- 

Industry a Result of Chemical Discovery 

It is interesting to learn that this process which France invented in her 
extremity became one of the largest industrial developments in England. 
It caused the flourishing there of the sulfuric acid industry because this 
acid was necessary for the process and, as we have seen, sulfuric acid is 
tremendously valuable in a great variety of directions. It also made 
possible the development of an enormous textile industry because the 


making of cloth needs soap and bleach, both of which were first supplied 
in abundance as a consequence of Le Blanc's discovery. 

To return to the story of the chemist's transformations of salt, the 
present process for the conversion of this compound into sodium car- 
bonate is by the action of ammonia and carbon dioxide upon a saturated 
solution of it, the carbon dioxide being obtained from limestone. When 
these three substances are brought together a change takes place which 
can best be described by the following equation: 

Carbon Ammonium 





NH 3 + 

H 2 + 

CO 2 

= NH 4 HCO 3 








NaCl + 

NH 4 HCO 3 = 

NaHC0 3 

+ NH 4 Cl 

The change that takes place depends on the fact that sodium bicarbonate 
is comparatively insoluble and separates out. It is collected and then 
heated, the heat causing it to turn into sodium carbonate, carbon dioxide, 
and water. 

2 NaHCO 3 = Na 2 CO 3 + CO 2 + H 2 O 

In this process the essential thing is to keep the ammonia in the system, 
because it is used over and over again and, if it escapes, an expense arises 
out of all proportion to the value of the carbonate which must be sold 
at a price of about two cents per pound. The ammonia goes out of the 
reaction, as indicated in the equation, in the form of ammonium chloride 
and this is returned to the process by allowing quicklime, made by heating 
limestone in kilns, to decompose the chloride. The other part of the 
limestone (the carbon dioxide) is also used in the process, as shown in the 
first equation. We start then with salt, water, and limestone, and we finish 
with calcium chloride and sodium carbonate. 

Caustic Soda 

This is not all that the chemist was able to do with salt. In soap making 
much better results are obtained if, instead of using wood ashes which 
give us nothing but an impure soft potash soap, we use sodium hydroxide 
or caustic soda. Now, caustic soda is something which does not occur in 
nature because it always combines with the carbon dioxide of the air or 
with some acid material and disappears. The old method of making it 
was to take the soda of the Le Blanc process and to treat it with slaked 
lime. In this way we can make about a 14 per cent solution of caustic 
soda which is then evaporated if it is required in a more concentrated 


form. This method of making caustic soda was sufficiently economical to 
give us all that we needed at very reasonable prices, but eventually a 
better method was discovered. 

Caustic soda is NaOH, that is to say, it is water (HbO) in which one 
of the hydrogens has been replaced by sodium. If in any way we could 
make this reaction take place, NaClH- HOH = NaOH + HCl, we would 
get directly two products which we want. Unfortunately, it is impossible 
to get salt to exchange atoms in this way with water. However, a study 
of salt solutions showed that the atoms of sodium and chlorine were 
actually separated when in solution and that they also acquired a property 
which would allow of their segregation. They became electrically charged 
and it is always possible to attract an electrically charged body by using 
a charged body of opposite sign. If, then, we put the positive and the 
negative pole of a battery or another source of electricity in a solution 
of salt the chlorine will wander away to the positive and the sodium 
will wander to the negative pole. 


What takes place can best be described by a rough analogy. Suppose 
two automobiles of different makes are running side by side, keeping 
together because of the friendship which exists between the two parties. 
Now suppose these two machines have an accident in which, by a freak, 
one wheel is torn off one car and added to the other. Assume that the 
occupants of the car are not damaged and that the cars can still run; also 
that the fifth wheel is a distinct nuisance. If there were two garages at 
considerable distances, one of which specialized in taking off extra wheels 
and the other did nothing but put on missing wheels, and the accident 
were a common one involving thousands of machines, then it would be 
natural for the cars to move in opposite directions to these two garages 
and if we assume that all the wheels are interchangeable, then there 
might be a traffic between the garages, by another road perhaps, the 
wheels being sent from one to the other. 

This very rough picture is intended to describe the fact that when the 
sodium and chlorine atoms of salt are separated by water the electrons of 
which they are composed are distributed in such a way that there is an 
extra one in the chlorine which (an electron being negative) makes the 
chlorine particle negative, while the sodium lacks one electron and there- 
fore becomes positive since it was neutral before. The result, then, of 
this electrolysis or use of the electric current in separating the charged 
atoms of sodium chloride (the ions as they are called) is that sodium and 
chlorine are given off at the two poles. Now, chlorine is not very soluble 


in water and can be collected as a gas. The sodium, on the other hand, 
as each little particle is liberated, reacts with the water about it to give 
hydrogen and sodium hydroxide. Therefore, we have accomplished what 
we set out to do, only instead of getting sodium hydroxide and hydrogen 
chloride we get sodium hydroxide, chlorine, and hydrogen. 


The success of this method is due to discoveries in another field of 
science. Only when Michael Faraday's researches on the nature of the 
electric current made available another source of energy different from 
heat, was it possible for the chemist to carry out what has just been 
described; at first only in a very small way but, as the production of 
electricity became more and more economical, ever on a larger scale until 
now the industry is a most important one. 


So far we have directed our attention almost entirely to the sodium 
atom of salt; the other part of the molecule, the chlorine, is also extremely 
valuable to us. It used to be set free by oxidizing hydrochloric acid of the 
Le Blanc process with manganese dioxide. Now, as we have just seen, we 
get it directly from a solution of salt by electrolysis. 

Uses of Caustic Soda 

The two servants which the chemist has conjured out of salt by using 
electricity are extremely valuable, though if they are not handled rightly 
they are equally as dangerous as they are useful when put to work. Caustic 
soda is a white, waxy-looking solid which is extremely soluble in water 
and attracts moisture from the air. It is highly corrosive, destroying the 
skin and attacking a great many substances. When it is allowed to act on 
cellulose in the form of cotton the fiber undergoes a change which results 
in its acquiring greater luster so that the process of mercerizing, as it is 
called, is valuable industrially. The manufacture of artificial silk made by 
the viscose method depends on the fact that caustic soda forms a com- 
pound with cellulose. Practically all the soap manufactured at the present 
time is produced by the action of caustic soda on fat. The by-product of 
this industry is glycerol which is used in making dynamite. In fact, soda 
is just as important among alkalies as sulfuric acid is among acids. 

Uses of Chlorine 

Chlorine, the partner of sodium, is a frightfully destructive material. It 
attacks organic substances of all kinds, destroying them completely, and 
it also attacks all metals, even platinum and gold, though fortunately, if 


it is quite dry, it does not react with iron, and on that account it can be 
stored under pressure in iron cylinders. Although it is such a deadly gas 
if allowed to run wild, yet it is extremely useful and its discovery has been 
very greatly to the advantage of the human race. First of all, it is employed 
in the manufacture of bleaching powder, a product which enables the 
cotton industry to work far more intensively than it otherwise could. 
Formerly cotton was bleached by laying it on the grass, but that is much 
too slow for our present mode of life. In fact, we have no room for it 
because it has been calculated that the cotton output of Manchester, 
England, would require the whole county as a bleaching field and this is 
obviously impossible. Then came the discovery that this same compound 
could be used in purifying our water supplies of dangerous disease-breed- 
ing bacteria and this has reduced the typhoid death rate from that of a 
very dangerous epidemic disease to a negligible figure. Now, whenever 
the water supply of a city is questionable, chlorine is pumped right into 
the mains or else a solution made from bleaching powder is used. Twenty 
parts of bleaching powder per million is sufficient to kill 90 to 95 per 
cent of all the bacteria in the water. For medical use, a solution of hypo- 
chlorous acid, which is the active principle of bleaching powder, has been 
developed into a marvelous treatment for deep-seated wounds, and 
recoveries which formerly would have been out of the question are now 
possible. Chlorine is also used in very large amounts in making organic 
chemicals which the public enjoys as dyestuffs or sometimes does not 
enjoy as pharmaceuticals or medicines. 

All in all, the products obtained from the little salt cube are of extreme 
necessity and importance to every one of us and their utilization shows 
what can be done when men of genius devote themselves to the acquisi- 
tion of real knowledge and then translate their discoveries into commercial 
enterprises for the benefit of humanity. 


The brief story for which we have space indicates but very dimly the 
real interest and fascination the chemist has in handling matter. His 
knowledge has increased to such a point that he can build you a molecule 
almost to order to meet any specifications. To be without any knowledge 
of chemistry is to go through life ignorant of some of the most interesting 
aspects of one's surroundings; and yet the acquisition of some knowledge 
of this subject is by no means hard. There are any number of books which 
tell the story in simple language if you do not wish to study the science 
intensively. On the other hand, all that you need is a real interest and a 
willingness to think as you read. 

The Chemical Revolution 


From Science Today and Tomorrow 


Grandma got by with a new bonnet and a smear of talc across her pretty 
little nose but times have changed. To make it easier for modern beauties 
we have assembled the Personal Spectrum Kit with all related cosmetics to 
suit your individual coloring. 

From an article by Edsd Ford, exploiter of soy beans and builder of 
motor cars: 

Our engineers tell us that soy-bean oil and meal are adaptable to by far 
the greater part of the many branches of the whole new plastic industry, 
and that shortly we are to see radio and other small cabinets, table tops, 
flooring tile in a thousand different color combinations, brackets and sup- 
ports of a hundred varieties, spools and shuttles for the textile trades, 
buttons and many other things of everyday use all coming from the soy- 
bean fields. 

From an address by the director of an industrial research laboratory: 

In 1913 the most carefully made automobile of the day had a body to 
which twenty-one coats of paint and varnish were applied. By 1920, 
through scientific management, it was possible to do a body-painting job 
in about eleven days. In 1923 came the first nitrocellulose lacquers. They 
cut the time to two days. Now a whole body is made out of metal and 
coated with any color in a day. 

From a German scientific magazine: 

Over twenty-five years ago the German chemist Todtenhaupt patented 
a process to convert the casein of milk into artificial wool. Under the 
economic stress of the Ethiopian war the Italians developed the process and 
by October 1936 will produce several hundred thousand pounds annually 
of artificial wool. No one pretends that it is indistinguishable from natural 



wool. It is still imperfect, but no more imperfect than were the first fibers 
of artificial silk. It meets men's needs all that can be reasonably de- 

Cosmetics, soy-bean products, lacquers, casein "wool" all are "syn- 
thetic," as the term is somewhat loosely used nowadays. There are thou- 
sands more like them, transformations of such familiar raw material as 
coal, petroleum, wood, slaughterhouse refuse. Indeed, every article that we 
touch is a chemical product of some kind, and many a one has no counter- 
part in nature. 

Despite a million chemical compounds known to technologists, despite 
the manifest artificiality of clothes, houses, vehicles, food all the result of 
chemical progress we have made but a beginning in the creation of a new 
environment. If the test of a culture based on science is the degree of its 
departure from nature woven cloth instead of skins, gas in the kitchen 
instead of wood, electric lights instead of naked flames, rayon instead of 
silk we are still chemical semi-barbarians. 

It is beside the mark to argue that a culture consists of something more 
than plastic compounds that take the place of wood and metal. Our society 
is what it is just because the engineer and the chemist have struggled with 
nature, torn apart her coal, her trees, her beauty, discovered how they were 
created, and then proceeded to make new combinations of their own. The 
lilies of the field and the honey of the bee are not in themselves sufficient. 
On every hand there is synthesis and creation scents, fabrics, drugs, plas- 
tics, metals like aluminum, sodium, and a few thousand alloys that nature 
forgot to make when the earth was a cooling but still glowing ball, dyes, 
unmatched by any gleam in the iridescent feathers of a peacock's tail, high 
explosives, lung-corroding gases, talking-machine records made of carbolic 
acid derivatives or artificial resins. 

More than the substitution of a synthetic for a natural product is in- 
volved. Buttons that look like ivory or bone but are neither, fibers that 
mimic silk but are better, automobile upholstery that passes for leather 
but is a form of guncotton, photographic films that bring the same screen 
plays to tens of millions simultaneously for as little as 25 cents these are 
the outward evidences of a breaking down of social distinctions, of a pro- 
found change in life. Gunpowder made all men the same height, said 
Carlyle in a fine but unwitting comment on chemistry. The leveling is not 
yet ended. 

New industries came with the rise of chemistry, and with them new 
opportunities for the many. There is a closer relation between democracy 
and the laboratory than the historians recognize. The environment has 


been chemically changed, and with that change has come a new vision of 
the social future. Is the world ready? 

Already a beginning has been made in three-dimensional chemistry. The 
potentialities are infinite, breath-taking. Suppose you want something as 
transparent as glass but as strong as metal. A three-dimensional chemistry 
may achieve it. There is even the possibility that active compounds may 
be devised active in the sense that they would shrink from blows or 
electric shocks just as if they were alive. 

Much so-called synthesis is merely a transformation of some natural 
product. Yet it is an evidence of social and scientific progress. It was a tre- 
mendous step from killing an animal and wearing its skin for protection 
to weaving a fiber on a deliberately invented loom, and thus making a soft 
pliable fabric. But the fibers were nature's after all. 

Indians once froze on ledges of coal. Mankind leaped ahead when 
inventors showed how coal could be used to raise steam and drive an 
engine. But the new conception of coal is chemical. It is a conception of 
cosmetics, alcohol, drugs, strange artificial sugars, a million useful com- 
pounds. So with wood. It is no longer a material out of which tables and 
chairs and houses are built, but cellulose, which can be reconstructed to 
assume the form of shimmering, silk-like filaments, cattle fodder, explo- 
sives. . . . 

Perhaps the most imminent of all the changes that the chemical revolu- 
tion will bring about will affect the materials of engineering. This age of 
power also is the age of steel. Age of rust would be a better designation. 
If it were not for our paints and protective coatings nothing would be left 
of this machine civilization a hundred years hence. No less an authority 
than Sir Robert Hadfield has estimated that 29,000,000 tons of steel rust 
away every year at a cost to mankind of $1,400,000,000. And this is not all. 
To produce every pound of this metal, lost by conversion into oxide, four 
pounds of coal had to be burned. The chemical revolution has already 
ushered in the age of alloys, many of then non-corrosive. There are 2000 
of them, and we have nardly begun to create all that the world needs. 
Parts of gasoline engines are now made of aluminum alloys. All-metal 
airplanes have for years been made of duraluminum a strong, tough, 
artificial metal. Aluminum alloys can be made as strong as steel. Very 
rapidly they are making their way in industry. 

What a tremendous amount of energy is wasted in hauling, lifting, and 
spinning unnecessarily heavy masses of metal! It costs now 5 cents a pound 
a year to move the dead weight of a street car. Think of the solid steel 
trains hauled by solid steel locomotives, of automobiles made largely of 
steel, of cranes that must be made of tremendous size and power to Hit 


gigantic masses of steel machinery! Tradition has obsessed us with the 
notion that weight and strength are synonymous. Gradually the metal- 
lurgist is breaking down this old conservatism. 

Ten thousand years ago, indeed until very recently, the metallurgist was 
a random smelter and mixer of metals. Bronze was one of his magnificent 
accidental discoveries. But how different today! With X-rays he peers right 
into the heart of a crystal for nearly everything in the crust of the earth 
is crystalline and sees how the atoms are placed. He juggles temperatures 
relates them to such properties as toughness, magnetism, lightness. He 
makes a mixture of aluminium, nickel, and copper. The result is a 
magnet that can lift a hundred times its own weight or an alloy so light 
that stratosphere balloon gondolas are made of it. 

Already he has reached the stage where he can synthesize a metal for a 
special purpose. Suppose he were to design and build an alloy with five 
times the tensile limit of any we now have not a wild impossibility. When 
he succeeds, "the art of transportation on land and sea will be revolu- 
tionized and, unfortunately, the methods of warfare," thinks Dr. Vannevar 
Bush of the Massachusetts Institute of Technology. 

Many of these alloys still to be discovered will be used in the home. 
Wood as a structural material is already doomed. Two centuries hence an 
ordinary white-pine kitchen chair of today will be treasured as an almost 
priceless antique. Quarried stone will be used only for buildings near the 
quarry. For the most part our houses will be cages of rustless alloy steel, 
around which cement or some other artificial plastic material will be 

Furniture will be made of a beautiful synthetic plastic material, a com- 
bination of carbolic acid and formaldehyde discovered and first applied 
industrially by a Belgian chemist, Dr. L. H. Baekeland, which is destined 
to become so cheap that it will compete with wood. The panes of the 
windows through which sunlight streams and the glassware that glitters 
on the carbolic acid-formaldehyde sideboard will be made of a scratch- 
proof synthetic product of organic chemistry which will be transparent, 
insoluble in water, and unbreakable. 

Draperies, rugs, bed and table "linen" by the year 2000 will be tissues 
of synthetic fibers. Washing will be obsolete. Bedsheets, tablecloths, and 
napkins will be thrown away after use. Draperies and rugs will not be 
cleaned, for as soon as they show signs of dirt or wear new ones will take 
their places. The household of the chemical future will probably spend no 
more in a year for its fabrics than it does now for mere laundering. Hence 
housework will be reduced to a pleasant minimum involving scarcely more 
than the dusting of synthetic furniture and the mopping of synthetic floors. 


Synthetic, too, will be the apparel of those who will live this easy life, 
Cotton, silk, wool, and such fibers as linen will still be spun, but only the 
very rich or the very snobbish will buy the fabrics into which they are 
woven. Such material will be as unnecessary as are the expensive furs in 
which fashionable men and women still clothe themselves mere survivals 
of a picturesque time when animals had to be skinned or clipped to make 
a suit of clothes. Already the silkworm is doomed as an adjunct of indus- 
try. Time was when only the worm knew how to change the woody 
tissues, or cellulose, of a tree into glossy threads. Now the chemist converts 
the tree into rayon and even makes silk, or something very like it, out of 
coal, limestone, and nitrogen. 

Synthetic wool is a commercial reality. The achievement was inevitable. 
Perhaps within ten years, certainly within twenty, a man will buy a ready- 
made suit of synthetic wool as warm as any now made from natural wool, 
and free from shoddy, and $10 will be a high price to pay for it. Even the 
most knowing sheep would be deceived by the yarn. There will be the 
same "feel," the same fluffiness and waviness. 

This $10 suit is almost attainable now. In the more distant future syn- 
thetic fibers still to be evolved will completely revolutionize tailoring. The 
cheapest suit of clothes is now stitched. What if machines do most of the 
sewing and if buttonholes are mechanically formed and finished ? The cost 
is high. Suppose we assign to the chemist and the efficiency engineer this 
problem of keeping the body warm and the person presentable. The first 
step is to abandon the old tradition of durability. Why must even the 
cheapest suit last at least a year? Is not the standard merely a heritage from 
a time when money was scarce and when a suit of clothes simply had to 

The synthetic chemist proceeds to create new fibers. Cheapness is his 
goal. His threads may be lacking in tensile strength and therefore in 
durability. But the fabric into which they are woven is not intended to last 
a year. Something much cheaper than artificial silk or wool is produced. 
In fact, it is so cheap that a suit can be made for a dollar a suit that will 
be as ephemeral as a butterfly and will be thrown into the ash barrel in 
two weeks. . . . 

"* The synthetically clad man of the future will surely nourish himself on 
synthetic food. Ultimately even the soluble dish will be regarded as an 
interesting heirloom of a still fairly savage past when man chewed vege- 
tation which had been boiled or baked, and actually killed and roasted 
animals for the sake of their proteins. But the year 2000 seems much too 
early a date for the achievement of synthetic nutriment, considering the 
staggering difficulties that the chemist must overcome. . . . 


Jets Power Future Flying 


-1L a windswept forest fire, your oil burner, or a jet plane of the future. 

There's simplicity in a stream of speedy gas pushing an airplane for- 

Jets with their simple power are revolutionizing travel through the air 
for peaceful transport or for atomic war if we fail in our attempt to get 
along with the other peoples of the world. 

Applying jet propulsion to our airplanes is the high priority task for 
our research laboratories today. Already the P-8os, with turbine-jet engines, 
have made obsolete the best conventional fighter planes with the best in- 
ternal combustion engines. Jet bombers are being flown experimentally. 
Jet transport planes are on the drawing boards. 

The reciprocating, spark-fired internal combustion engine feeding on 
gasoline (look under the hood of your automobile to see one) has a rival 
that may drive it out of the air. 


There are four different types of jet-propulsion units: 

The turbo-jet and turbo-propeller-jet engines, which operate through 
the principle of the gas turbine. 

The pulse-jet, used by the Germans as the propulsion unit of the V-i 
"buzz" bomb. 

The ram-jet, currently undergoing rapid development for use on guided 
missiles or other highspeed transportation. 

The rocket, most highly developed in the German V-2 weapon. 

Only the turbo-jet and turbo-prop-jet engines rely upon gas-turbine- 
driven compressors to compress the intake air. The pulse-jet and the ram- 
jet use oxygen of the air for burning their fuel, but compress the air by 
their speed. The rocket supplies its own oxygen and thus can go outside 
the atmosphere. 



The principle of the combustion gas turbine is not new, but it makes 
possible the development of turbo-jet and turbo-prop-jet engines for air- 
craft. The future of marine and railroad locomotive propulsion will feel 
its impact. History is full of attempts to develop a satisfactory gas turbine. 
Early experimenters were unsuccessful. They were handicapped both by 
lack of knowledge which would permit design of efficient compressors 
and turbines, and by lack of the proper materials of construction. 


The wartime need for greater and greater speed in aircraft prompted 
intensive research that before and during the war increased our knowledge 
of aerodynamics. Metals were devised that would stand up for extremely 
high temperatures. This made possible the development of the gas turbine, 
in the form of the turbo-jet engine, for aircraft. This new type of engine 
is one of the outstanding developments since the Wrights flew the first 
heavier-than-air machines. 

The design of the combustion gas turbine is simple. There is only one 
major moving part, a rotating shaft on which is mounted an air compressor 
and a turbine rotor. The compressor supplies air to the combustion cham- 
bers where fuel is burned continuously to increase the energy content 
of the compressed air by heating it. The resulting hot gases are then ex- 
panded through a turbine. The turbine rotor and shaft revolve. In the case 
of the turbo-jet engine, only sufficient energy is recovered by the turbine 
to drive the compressor, and the hot gases leaving the turbine are exhausted 
through nozzles to form the jet. The reaction to the jet propels the air- 
craft as a result of the increase in momentum of the air stream due to its 
rise in temperature and volume as it passes through the unit. 

In the prop-jet engine, the greater part of the energy available in the 
hot gases from the combustion chamber is recovered by the turbine. The 
power thus available, over and above that required to drive the compressor 
is utilized to drive an air screw propeller, in the case of high-speed aircraft. 

Great amounts of fuel and air consumed by the gas-turbine engine in de- 
veloping its great power are astounding. Philetus H. Holt, a research direc- 
tor of the Standard Oil Development Co., has figured that a turbo-jet 
engine developing 4,000 pounds thrust, equivalent to 4,000 horsepower at 
375 miles per hour, will require more than 4,000,000 cubic feet of air in an 
hour. At this rate, all the air in a typical six-room house would be exhausted 
in about nine seconds. Approximately 20 barrels of fuel are burned each 
hour enough fuel, if it were gasoline, to drive an automobile 12,000 miles 
at a speed of 60 miles per hour, or, if heating oil, enough to heat a typical 
six-room house for two-thirds of a heating season. 


Heat is released in the combustion chambers of the turbo-jet engine at 
the rate of about 20,000,000 Btu. per hour per cubic foot of combustion 
zone, which may be compared with a rate of one to two million Btu. per 
hour per cubic foot in the case of industrial furnaces. This great develop- 
ment of power is accomplished with a freedom from vibration unknown 
in reciprocating engines. 


Where fuel economy is of secondary importance, the turbo-jet engine 
far surpasses the conventional reciprocating engine when high speed at 
present altitudes is necessary, as is the case in fighters, interceptors, and fast 
attack bombers. When pressurized cabins are used combined with turbo- 
jet power at very high altitude, fast, long-range commercial transports will 
be attractive to airlines. At altitudes of 40,000 feet or higher the turbo-jet 
unit is much more economical of fuel than at low altitudes. 

Long flights of 3,000 miles, which presently take 12 to 14 hours, will be 
made in six to seven hours. Equipment and pilots will do double jobs; pas- 
sengers will get there faster. 

The turbo-propeller-jet power plant has the possibility of competing 
directly with the conventional reciprocating engine at present-day speeds, 
since improvements in design should soon give fuel economy and operating 
life equivalent to those of the reciprocating engine. 

How soon will your airlines ticket give you such flight ? Some estimate 
they will come in three years, others in five years and others still 10 years 
or longer. The rapidity of their introduction, say the engineers, will be in 
direct proportion to the amount and calibre of the effort expended in re- 
search and development. 

Turbo-jets will do their job at double the speeds of present airlines, but 
aviation will turn to the ram-jet to surpass the speed of sound. 

Speeds twice the speed of sound, some 1,400 miles per hour, have been 
achieved for short flights by the "flying stovepipe." 

Jap Kamikaze "suicide" planes sparked the post-haste development of 
the ram-jet to power the Navy's "Bumblebee" anti-aircraft weapon that 
would have been shooting them down if the war had lasted. 

The ram-jet idea is not new, although, like other modern jet engines, it 
is 20th century in its conception. Rene Lorin, a Frenchman, proposed in 
1908 the use of the internal combustion engine exhaust for jet propulsion, 
and in his scheme the engine did not produce power in any other way. 
Five years later he described a jet engine where the air was compressed 
solely by the velocity, or ram, effect of the entering air. This is the ram-jet. 

The nickname of the ram-jet, "flying stove-pipe," describes what it looks 


like. It is a cylindrical duct, with a varying diameter. The air enters through 
a tapered nosepiece and it comes in at a speed above that of sound. The 
ram-jet is only efficient when it goes through the air at speeds higher than 
the speed of sound, which is about 700 miles per hour. In the military 
version of the ram-jet, it is launched and brought up to speed by rockets 
which soon burn themselves out and give way to the ram-jet itself. 

Air entering the tube when the ram-jet is in flight is slowed down to be- 
low the speed of sound. The air mixes with the fuel. The very simple de- 
vice for doing this is at present one of the secrets in the ram-jet, as applied 
as an anti-aircraft weapon. The diflfuser in the air duct stabilizes the 
flame and the combustion of the gases increases very rapidly through the 
duct. Just to the rear of the ram-jet the gases attain a speed of up to 2,000 
miles per hour. 

When supersonic transportation of mail, express and ultimately pas- 
sengers is contemplated, the ram-jet offers a motor of great promise. The 
present military development of this device is by commercial and industrial 
agencies, under sponsorship of the Bureau of Ordnance of the Navy, with 
the coordination of the Applied Physics Laboratory of the Johns Hopkins 
University. This development may influence peacetime transportation of 
the future world. 

In the future, liquid fuels that are produced from petroleum will be made 
to fit the requirements of jet engines. Particular fuel requirements for the 
turbo-jet engine may even bring kerosene and other distillates heavier 
than gasoline back into prominence. 

During the war some of the jet planes were designed to burn kerosene 
while other jet devices operated on hundred octane gasoline. Such high oc- 
tane gasoline was not actually necessary but due to the fact that much of 
the aviation fuel in the war areas was high octane, it was used to simplify 
the problem of supply. 

If jet planes were used in another war emergency, a fifth of the U. S. 
petroleum refining capacity would be used for making jet fuels, Robert 
P. Russell, president of the Standard Oil Development Co., estimated re- 
cently. Designing of fuel that can be used in a variety of jet motors is as 
important as designing jet motors themselves. Military specifications are 
now being considered that will cause more of the fractions of petroleum 
to be used in making jet fuel. This may prove to be one of the most im- 
portant decisions affecting flying power for the future. 


Science in War and After 


From Atoms in Action 

JL of the air is the Douglas -19 bomber designed for the U. S. Army, 
which made its first flight early in 1941. The yoton weight of this great 
plane, twice as heavy as the famous Atlantic Clipper ships, is borne by 
wings stretching 210 feet from side to side. With 11,000 gallons of gasoline 
in its tanks to feed the four thirsty engines which release 2000 horsepower 
each, this giant plane can carry 28 tons of bombs to a point 3000 miles 
away, and return without re-fueling. 

Though the trend will probably be toward even larger battleships of 
the air, there is a limit to the weight of airplanes which can alight on 
land. When the yo-ton bomber is on the ground its entire weight must 
be supported on its wheels, and these are large and unwieldy in the 
extreme. In fact, the only accident to the first of these great bombers 
occurred when one of its wheels sank through a macadam pavement. 
Pontoons rather than wheels will avoid this problem, and it seems likely 
that the giant flying battleships of the future, if such there must be, will 
rest on water when not in the air. 

The tremendous destruction produced in Europe during the present 
war by falling bombs is likely to lead one to think that the bomber has 
everything his own way. This is becoming increasingly less true as defen- 
sive measures are perfected. Entirely apart from this, the bomber who is 
trying to destroy an important target is faced with a difficult problem at 
best. Airplanes do not stand still in the air, or even travel in straight lines 
when anti-aircraft shells are bursting around them, and to hit a target 
five miles below from a platform moving erratically through the air at 
400 miles an hour requires more than mere skill. It requires the assistance 
of cleverly designed scientific apparatus hence the great secrecy regard- 
ing bomb-sights. 

A bomb dropped from a plane strikes the ground far ahead of the point 
directly under the position of the plane when the bomb was dropped. 



Since the bomb when released is moving forward with the plane, usually 
as fast as a revolver bullet, it falls to earth in a broad parabola. During the 
twenty or more seconds which elapse while it is falling, it may travel 
more than two miles forward. In addition, cross-winds at various levels 
can in twenty seconds blow the bomb far to one side or the other. Various 
bomb-sights have been developed which enable the pilot quickly and 
automatically to allow for these effects. These are complicated combina- 
tions of telescope, speed indicator, and computing machine whose details 
are kept rigorously secret by the various powers. 

During the first few months of the aerial bombardment of Britain in 
1940 the German bombers seemed invincible, but gradually the funda- 
mental truth, that for every new offense there is a satisfactory defensive 
answer, has been borne out. First came the defeat of the day bomber by 
the pursuit plane, and when losses during each daylight raid rose to 10 
per cent, the Germans were forced to restrict bombing operations to the 
hours of darkness, when pursuit planes could not find the bombers. 

Several months passed during which night bombing raids were the 
most pressing problem facing the British, but gradually hints began to 
appear which indicated that a solution of the night-bomber problem was 
imminent. At the end of 1940 the Air Chief Marshal announced that a 
method for frustrating night bombers had been found, and in June of 
1941, the basis of the method was made public. It was the radio-locator, 
and this, widely publicized as Britain's secret defense weapon, gives an 
excellent example of the use of science in defensive warfare. As far as an 
enemy bomber is concerned the device is used to turn night into day. If 
no light waves are available to see with, says the scientist, look around 
for some other type of waves. 

Actually nature perfected a similar method of detecting night fliers long 
before the airplane was dreamed of. For hundreds of years bats have 
been able to fly about in pitch-black caves without colliding with each 
other or with obstacles in their paths. Scientists have stretched numerous 
criss-cross wires in a room, and then darkened the room completely before 
bats were brought into it, yet when the bats were released they flew 
blithely about without once striking against a wire. 

Careful tests showed that the bats were indeed flying blind, for when 
adhesive tape was placed over both eyes a bat could avoid the wires quite 
as well as with its eyes uncovered. Though the proverbial bat may be 
blind, it can steer at high speed quite as well as any sharp-eyed lynx. 

When adhesive tape was placed over the ears of the bats, however, the 


results were very different the uncanny power disappeared completely. 
Similarly were they handicapped if the power of hearing was restored, 
but their mouths were taped shut. 

Scientists found that the bats were constantly broadcasting high-pitched 
squeaks during flight, sounds so shrill that only occasionally could an un- 
usually low one be heard by human ears. These sounds were quite audible 
to the ears of the bat, and could of course be detected by special micro- 
phones. When several bats were set flying around a dark room in which 
only the flutter of skinny wings was audible to the crouching scientists, 
the microphone detectors showed the air to be filled with a shrill clamor 
of very short wavelength a super-sound related to ordinary tones as 
ultra-violet light is related to visible light. The human ear cannot hear 
waves vibrating faster than 20,000 times a second, but the bat language 
used for aerial navigation is found to be loudest at 50,000 vibrations a 

As a blind man walking along a sidewalk keeps tapping with his cane 
to produce sounds which will be reflected from walls and other obstacles, 
so the bat keeps broadcasting his shrill cries and these, reflected from other 
bats, walls, or even wires, come back to his sensitive ears and warn him 
of danger ahead. 

Though these super-sound waves will do very well for the navigation 
of bats, or even of boats, they would be of little help in steering airplanes 
in the dark, for these waves move no faster than ordinary sound waves, 
and we have already seen that a fast airplane flies at two-thirds of this 

Far more effective for this purpose, and capable of being used in the 
same way that bats use super-sound, are radio waves. These travel nearly 
a million times as fast as sound waves, and since airplanes fly only about 
ten times as fast as bats, this gives ample margin, providing science can 
furnish a means of responding to the reflected wave which is about 
100,000 times as fast as the response mechanism of the bat. This rapid 
response mechanism British scientists have been able to develop. 

To detect something with waves it is necessary that the waves used be 
not much longer than the object being detected. Therefore, to locate an 
enemy bomber having a wing span of 100 feet, one should use waves not 
much more than 100 feet long. Other factors make still shorter waves 
desirable, and radio waves only a few feet long, micro-waves, are found 
to solve the problem admirably. 

What an effective picture of the secret maneuvermgs of science this 
presents! Here we have German planes loaded with destructive bombs, 
five miles up in the air, swiftly feeling their way toward London by fol- 


lowing a beam of radio waves sent from a station behind them in France, 
Such beam flying has of course been used for years, and is a common- 
place feature of most airlines in peacetime. But how is the bomber to 
know when to drop its destructive cargo? From Norway or some other 
point making a wide angle with the first beam another radio beam is 
sent, directed to intersect the first beam directly over the target. When 
signals in his earphones tell the pilot that he has reached this intersection, 
he drops his load of bombs and turns to streak for home. Scientifically 
designed murder, to be sure, but this is not the whole story. 

Scattered all over Great Britain are short-wave radio stations which 
send beams of micro-waves toward the invasion coast. When the sky 
above France is clear of planes no waves are reflected to the sensitive 
receivers which the British keep constantly on watch. But when a plane 
rises into the air even 100 miles away, according to news reports, it reflects 
back some of the micro-waves, and thus can be detected in ample time to 
let interceptors take the air and be ready for it. 

So important was the radio-locator that it was officially given the credit 
of enabling the Royal Air Force to win the first defense of Britain. British 
scientists had been working on the method for five years or longer, and 
scientists everywhere are gratified that this most spectacular secret weapon 
is of purely defensive value. The principle was available to the Germans 
and was doubtless known by them, but this lessens its value to the British 
or any other defending community not one whit. 


There are times when a new type of camera is more important to an 
army than a new type of gun, and when a good photographer is of greater 
value than an able sharp-shooter. Before and during an intensive cam- 
paign dozens of planes may fly over the enemy lines every day without 
dropping a bomb or firing a shot. These planes contain complex oversized 
cameras with which pictures of the terrain are taken, to detect any 
changes in its appearance since the previous flight. The eye of the camera 
has a great advantage over that of any human observer, for not only can 
it absorb an entire scene in a few thousandths of a second, but it brings 
back a record of what it saw which is permanent and far more revealing, 
when examined slowly and in detail, than the most lingering glance of 
an observer in an airplane. Films taken on two successive days can be 
superposed in such a way that differences between the two a departed 
ship, a freshly bombed oil-tank, or newly camouflaged artillery will 
stand out vividly from an unobtrusive background of details common to 
both photographs. 


Reconnaissance planes are as vulnerable to attack as any others, so they 
must fly as fast and as high as possible. Great altitude requires provision 
of giant cameras, weighing several hundred pounds and costing more 
than $5000 apiece, with very large lenses. To take a photograph from a 
height of several miles which will reveal details as small as a man requires 
the use of a lens consisting of four to six carefully shaped pieces of the 
finest glass, each as large as a dinner plate. Such a camera is, in fact, a 
telescope of sufficient size to delight the heart of almost any astronomer. 
To provide a shutter big enough to cover such a lens, which can yet open 
and close within a few thousandths of a second, requires careful scientific 
designing, yet this is necessary if the photographs are to be brilliantly 
sharp and clear. 

When flying a reconnaissance plane, a pilot must be prepared to level 
off at some definite height and fly a long, straight course while photo- 
graphs are being taken. When a red light starts blinking on his instrument 
panel, the pilot knows that he must fly the ship on an even keel so the 
photographer can snap mile after mile of enemy territory, taking several 
hundred pictures on a single roll of film. Automatic timers are sometimes 
used, which click the shutter at any desired regular interval. It was com* 
mon knowledge in 1941 that every day hundreds of miles of the "invasion 
coast" of France was thus photographed by the Royal Air Force. From 
some of the planes used for this purpose pictures were taken at an altitude 
of more than five miles. By using multiple cameras in which each click 
of the shutter took nine pictures through as many lenses, an area as great 
as 900 square miles was photographed with each exposure. 

The greater the altitude from which photographs are taken, the more 
likely is the ground beneath to be partially hidden by haze. Light scattered 
from this haze changes what would otherwise be a crisp and vivid picture 
into one of dull uniformity and low detail. Longer waves than those our 
eyes can see will be less scattered by the haze, and for this reason infra-red 
photography has become of great importance in modern warfare. But 
longer exposures are required when the specially sensitized film needed 
for infra-red exposures is used. For this reason all the armies of the world 
have been concerned with the development of infra-red film of increased 

As enemy territory* becomes more thoroughly protected by fighter 
planes during daylight hours, it becomes increasingly difficult to take the 
desired reconnaissance photographs each day. Therefore, the trend is 
toward more night photography, when darkness lends to planes increased 
safety from antiaircraft fire and aerial pursuit. Thus flashlight photog- 
raphy has been brought into warfare, but flashlights on what a scale 1 


Instead of filling with light a small room or even a huge auditorium, the 
flash must illuminate the whole of outdoors! 

To make an area of many square miles as bright as day, even if only 
for an instant, army photographers have developed amazing flashlights 
which consist of great sacks full of magnesium powder, wafted slowly to 
earth by small parachutes. When the photographer wishes to take a pic- 
ture, he merely tosses a sack of the powder over the side of his plane. The 
parachute with which the sack is provided opens automatically, and a 
fuse is set off which explodes the bomb a few seconds later, after the 
powder has had time to fall the desired distance below the plane, and has 
lagged sufficiently behind it. A blinding flash of light comes from the 
exploding powder, and the first light from this flash strikes a phototube 
on the plane, and immediately opens the shutter of the camera. Events 
are automatically timed so that the shutter opens just as die landscape is 
most brightly illuminated. 

Camouflage the art of concealment by merging an object with its 
surroundings, or by making it appear to be what it is not requires in- 
creasing cleverness if it is to withstand successfully the searching eye of 
the camera. An outstanding example of this occurred in July, 1941, when 
the British published photographs showing how the Germans had at- 
tempted to mislead them into bombing an innocuous block of houses in 
Hamburg instead of the great railroad terminus which the British were 
seeking. A bridge over a narrow body of water pointed directly at the 
railway station, and this the British airmen had been using as a landmark. 
The ingenious and industrious Germans covered the offending body of 
water as far as the bridge with rafts carrying false houses, and a short 
distance away installed a false bridge which pointed at the block destined 
for sacrifice in place of the station. This device might have succeeded had 
not the superposition of photographs taken before and after the alteration 
revealed the shift. 

The stereoscopic camera, with two lenses giving a pair of photographs 
which, when viewed properly, merge into one which has depth and a 
lifelike appearance of solidity, is especially valuable in revealing camou- 
flage of a common type. On developing photographs of a certain enemy 
flying-field, British officers found that something looked queer about a 
group of airplanes packed closely in one corner of the field. The planes 
looked ordinary enough when viewed from the air, and in the usual 
photographs, but when a stereoscopic camera was used they appeared 
quite flat and lifeless in the resulting views, instead of sticking up from 
the ground as they should. It is not difficult to imagine the feelings of the 
soldiers who had diligently fitted together boards in airplane shapes, laid 


them on the ground, and painted them, when next day a lone bomber, 
sailing over on the way to deeper-lying territory, carefully dropped two 
wooden bombs on the field. 

Of great value in detecting camouflage of another sort is color photog- 
raphy, but strangely enough, ordinary color photography often is not 
so useful as partially color-blind photography. Certain commanders were 
surprised to find that one or two of their aerial observers were able to 
detect four times as many camouflaged objects behind the enemy lines 
as most of their observers could see. Tests showed that the abnormally 
sensitive observers were color-blind. 

The explanation was not far to seek. The camouflaged objects had been 
carefully painted by soldiers with normal vision, who had matched their 
paints in color with the surrounding green foliage. The color-blind ob- 
servers, however, could not see green anyway. The greenness which, to 
a person of normal vision, obliterated lesser differences between paint 
and foliage, was eliminated in their eyes, leaving contrasts of redness or 
blueness or tone or shade to stand out vividly. 

This discovery caused many articles to be published stating that color- 
blind persons would be in great demand as aerial observers. Such was not 
the case, for although it is impossible to give normal color-vision to a 
person who is color-blind, it is quite easy to give artificial color-blindness 
to any person with normal vision. All that is needed is to equip him with 
a pair of colored glasses which will absorb light of the color he is not to 
see. A pair of magenta lenses will make him green-blind, for no green 
light can traverse them, while blue lenses will make him red-blind. Such 
colored glasses have indeed been found of great value in aerial observation, 
and the really scientific camoufleur should use a spectroscope to be sure 
his paints match the foliage for any light waves that may strike them. 
To make the match complete with surroundings, he must include the 
invisible ultra-violet and infra-red waves as well as those which the eye 
can see, for the eye of the camera can see several octaves of color, whereas 
the human eye can see but one. By using the proper color filters on his 
scientifically equipped camera the aerial photographer can ferret out any 
object in which all colors, invisible as well as visible, have not been closely 
matched with those of the surroundings. 


The tank, introduced by the British during the first World War and 
since developed by other nations into a formidable juggernaut, is the 
modern scientific equivalent of the armored knight of the Middle Ages. 
Because spices had to be used instead of refrigerants to keep meat palata- 


ble in those days, and because nothing was known about balanced diets 
and vitamines, the medieval knight was rather a stunted fellow by mod- 
ern standards. Most of the suits of armor preserved in museums are found 
to fit men less than five feet six inches tall. 

Even the most colossal knight would not have been strong enough to 
carry armor of sufficient thickness to withstand modern high-power 
bullets, however. To be sure, he could clothe himself and his staggering 
horse in heavy armor, but once dislodged he became powerless. What 
more reasonable than to substitute an automobile for the horse, use tractor 
treads to cover rough ground at high speed, and put the armor on the 
resulting tank instead of on the man? 

The tank, like the airplane, is undergoing a period of rapid engineering 
development, with scientists concerned principally in making its armor 
tougher and more resistant to penetration. The larger a tank is made, the 
more powerful can its engine be, and the greater the proportion of its 
weight which can be used for defensive armor and offensive armament. 
A bullet an inch and a half in diameter was formerly big enough to punch 
holes in a tank, but now shells three inches in diameter are necessary. 
Thus y-ton light tanks must give way to 25-ton medium tanks, which in 
turn retire before the great 80- and zoo-ton tanks now being introduced. 

There is a limit to the concentration of weight which soil can hold, 
however, and if the weight of a tank is to be increased its treads must 
cover a larger area. But the larger the tank the less strong does its un- 
wieldly bulk become. Like the dinosaur, too large a tank is impractical, 
and may ultimately collapse of its own weight. For this reason the battle- 
ship of the land can never expect to compete with the battleship of the 
sea, which, like the whale, is supported in depth as well as in area. Land 
tanks weighing 200 tons may become practicable, but to hold 40,000 ton 
tanks, a liquid is the only suitable medium. 

On the sea, armor plate can really come into its own, and a solid two- 
foot thickness of the toughest steel can be used to make an almost 
impenetrable barrier. The resulting battleship spends most of its life in 
harbor, or cruising about merely existing as a threat to lesser vessels, 
waiting for the few minutes or hours when it may be in action. Then 
precision of fire is of the utmost importance, and the fate of a whole navy 
or nation may depend on the extra thickness of a hair by which the 
muzzle of a i6-inch rifle is elevated. The enemy is to be struck if possible 
before his shells can strike back; no useful development of science which 
will bring this about is considered too expensive. 

Between 1911 and 1941 the biggest rifles used by the navies of the 
world have swelled from 12 inches in diameter to 17. This has made 


possible the hurling of tons of steel 28 miles instead of a mere n, with 
a vast increase in accuracy. No navy expects to hit its target at the first 
salvo, which must be considered as several thousand dollars spent to find 
out how the wind is blowing and how accurately certain intricate cal- 
culating machines have been used to determine range and direction of 
aim. In the better navies the target is supposed to be struck on the third 
salvo, but the second is becoming increasingly useful as better scientific 
methods of measurement are brought to bear on the problem. 

To hit a target 30,0000 yards away requires careful determination of 
the speed of both vessels, the angles of pitch and roll of the ship, the 
barometric pressure, the humidity of the air, and even the temperature of 
the powder loaded into the gun. To introduce all these factors involves 
extensive computing which, if done with pencil and paper, would require 
days to complete. Instead, great computing machines are used on which 
the temperature of the powder can be set in with one crank, humidity 
with another, range, speed, and the rest of the factors with others; then 
the wheels turn and the correct setting of the guns is calculated auto- 
matically within a few seconds. 

Before the calculating machines can be set into operation, careful 
measurements must be made with a dozen scientific instruments, and 
of these the range-finder is perhaps most interesting. This has the difficult 
task of measuring the distance to a target, which may be anywhere from 
half a mile to thirty miles away. A modern range-finder may contain 
1600 parts built with the utmost precision, and may cost as much as 
$40,000. In it are glass prisms whose sides are so true that if one were 
extended a distance of 80 miles, the line would be within a foot of its 
correct course. A modern battleship is likely to have at least four of these 
instruments, with two smaller ones pointed into the air to determine the 
heights of airplanes. 

There are several types of range-finders, but most involve a principle 
similar to that involved in telling how far away an object is by looking 
at it with both eyes open. Look at your finger held six inches from your 
nose and your two eyes will be turned in sharply; now look at something 
far away, and the eyes will turn so as to look in almost parallel directions. 

If human beings had eyes set farther apart in their heads than they 
now are, we would be able to judge distance more accurately than we 
now can. In the range-finder the two eyes may be placed as much as 
thirty feet apart, by using prisms to bend the light rays. Two telescopes 
are set into opposite ends of a long tube, and the light which comes 
through these is sent by prisms and lenses into the two eyes of the ob- 


One of the telescopes always looks straight ahead, but the other can 
be swung through an angle to look at any object at which the other 
telescope may be pointed. The observer sees his target magnified as in 
an ordinary telescope, but everything above the middle of the image has 
come through one telescope, and everything below through the other. 
He can turn a handle until the two parts of the target come together into 
one well-fitted picture; then both telescopes are pointed directly at the 

The turning of the handle also operates a computing machine, which 
works out the mathematics involved in finding how far away an object is 
when the lines of sight of the two telescopes make a certain angle. The dis- 
tance to the target can be read directly from a dial which gives the correct 
answer no matter where the handle is set; thus ranges up to 40,000 yards 
can be read quickly to within one salvo pattern. 

Range-finders are usually placed high above the deck of a battleship, 
to enable them to peer over the bulge of the earth at distant objects. That 
the guns are many feet below the range-finders, and must be pointed high 
into the air rather than directly at the target, while they rock from side 
to side as the boat rolls and pitches on the waves, does not disturb the 
mechanisms charged with the duty of landing the first salvo close to the 

Even as early as 1935 Hitler had turned the major attention of German 
scientists to the search for new developments useful in war. As his threat 
developed other nations began tardily following suit. In Great Britain 
the demand of the armed services for physicists and chemists became so 
great in 1941 that these key scientists were not permitted to enlist as 
soldiers, but were drafted for laboratory work. A great shortage of 
trained scientists soon developed in all the warring countries. 

Recognizing that the most powerful weapons of offense and defense 
are furnished by science, the man in the street, particularly in America, 
has attempted to do his bit as an inventor. Since 1918, a Naval Consulting 
Board in Washington is said to have received 110,000 letters containing 
suggestions for improvements in naval defense, and a National Inventors 
Council was set up by the United States Government in 1940, to aid 
inventors who wished to make suggestions. Some of the ideas received 
were rather amazing, but a sufficient number to justify the effort of the 
board of experts who sorted them out were said to have merit. . . . 

A favorite field of amateur inventors in wartime is the "death ray," but 
this is a device on which scientists waste no time whatever. All that is 


needed to make a death ray usable is the discovery of a suitable ray. 
None of the agencies known to physicists at the present time is one- 
thousandth as effective in destructive action as the shell or bomb con- 
taining a powerful explosive, demolishing what it strikes by the impact 
of matter on matter. . , . 

Discussion of the responsibility of science for ills of the human race, 
of which the miseries of war are at present most striking, is to a con- 
siderable degree academic. We cannot be rid of science if we would, 
for science is, after all, nothing but knowledge, and it is doubtful that 
the human race has the ability to keep itself in everlasting ignorance, even 
if this should be proved desirable. Few persons would argue that igno- 
rance is desirable, but many point out that man's spiritual development 
has not kept pace with his material progress. This is obviously true, but 
blame for the situation can as justly be attached to the slowness of 
spiritual development as to the rapidity of material progress. Actually, 
of course, the difficulty arises from the fact that spiritual development 
comes only from human experience. Nature provides an automatic 
compensating mechanism, such that if material progress is too rapid, 
suffering results which accelerates spiritual progress. 

Most of the clamor against science arises, not from real worry about 
spiritual development, but because it is human nature to take benefits 
for granted, while complaining loudly against accompanying disad- 
vantages. It is of value to pause and note how easily these disadvantages 
are exaggerated. 

Much of the horror of modern warfare arises from the fact that 
hundreds of millions of people, through the agency of radio, motion pic- 
tures, and the daily press, are brought far closer in imagination to the 
battlefield than was ever possible before. Though more people do suffer 
as a result of warfare nowadays, a larger proportion of them suffer only 
mentally and in anticipation. 

Science, with its improved methods of communication, is responsible 
for the fact that the number of things we find to worry about is increas- 
ing from day to day. Science is, however, also responsible for the fact that 
there is an even more rapid increase in the fraction of these terrible 
things which never happen. . . . 

In what are sometimes called "the good old days," war, famine, and 
pestilence were considered inevitable. If half a man's family was wiped 
out in a week by diphtheria, that was the will of God. Now man has 
made use of his God-given opportunities to control famines which arise 


from natural causes. Through science the Black Plague, cholera, yellow 
fever, and a dozen other pestilences have been wiped out, and the 
rest are on the way. The twentieth century may well see war, this 
further "pestilence," eliminated, as through the natural sciences man 
gradually raises the level of availability of the things he needs for health, 
security, comfort, education, and enlightenment, by creating more and 
more order in nature. 

We hear much about the "good old days," but the world is growing 
older every day, not younger. Opportunity knocks on every hand for him 
who has ears to hear, and there is ample evidence that the best "old days" 
lie ahead. 

Edition of 1941 





earth, penetrated the atom. As yet we have not touched the World of Life. 

What is this Life? In what shadowy spot, as yet unknown, does the 
transition from the dead to the quick take place? We know many of the 
processes involved in living. We still do not know what life really is. W. /. V. 
Osterhout, the botanical scientist who has done much to push back the 
borders of the unknown, opens our discussion with The Nature of Life. He 
exposes many misconceptions, although he leaves the question unsettled. 
And yet, it is possible to see how living things exist in nature their chem- 
ical properties, actions and reactions, adaptation to environment, develop- 
ment and multiplication. That is the theme of The Characteristics of Organ- 
isms by Sir /. Arthur Thomson and Patrick Geddes. 

We can also trace the course of man's belief in the spontaneous origin of 
life, especially as it relates to the study of the smallest living creatures under 
the microscope. The study begins with Leeuwenhoek, Paul de Kruif s ac- 
count of the testy Dutchman who, looking through his homemade micro- 
scopes, was the first to see those tiny "animalcules" which we call microbes. 
The more he looked, the more he found in the tissues of a whale, the 
scales of his own skin, the head of a fly, the sting of a flea. He watched 
them attack mussels and so realized that life lives on life. It is doubtful 
whether he knew that life must always come from life or that microbes play a 
dominant role in disease. 

Those were discoveries that were to take centuries and test the abilities 
of men like Spallanzani, Redi, Pasteur, Tyndall, Koch. We no longer think 
that eels develop spontaneously in stagnant pools, that kittens (without 



parents) spring from piles of dirty clothes. The idea is so foreign to us that 
we hardly believe men could have thought it possible. Yet the classic ex- 
periments which disproved once and for all the doctrine of spontaneous 
generation were performed no earlier than the last century by Pasteur and 
Tyndall. Pasteur showed that water boiled in flasks to which the dust-filled 
air was not admitted would never generate life. He showed that flasks opened 
in Paris contained numerous microbes, while those opened in the Jura 
mountains contained few or none. "There is no condition known today/' he 
wrote, "in which you can afErm that microscopic beings came into the world 
without germs, without parents like themselves." 

Yet somewhere along the road, if we may believe the latest researches, life 
and nonlife seem to merge. The story is told in Gray's Where Life Begins. 
Here we observe viruses far smaller than anything seen by Leeuwenhoek, 
made up of molecules which may be composed of thousands of atoms. 
Are they alive? It depends on our definition of life. By some standards they 
are, by others they are not. Perhaps further in the direction which Stanley 
and others are taking, the answer lies. 

The work described in this contribution by Gray is among the most 
important scientific investigations of our day. No matter what the results, 
however, it is doubtful whether they will resolve the conflict between the 
mechanists and the vitalists. The vitalists will continue to claim that there 
is something more fundamental than molecules and atoms. And, like 
Pasteur in the last century, the mechanists may be counted on for new facts 
to meet each new stand of their opponents. 


Plants and animals differ from one another in myriad ways and the most 
obvious is that of size. We do not often stop to analyze this difference, as 
Haldane does so amusingly in On Being the Right Size. Haldane is a famous 
geneticist, but he is also a writer of charm and wit. If you've ever been fear- 
ful that insects might grow large enough to dominate man, or been puzzled 
why mice could fall down mine shafts without injury, or wondered why there 
are no small mammals in the Arctic, here is your answer. As there are dif- 
ferences, so are there similarities at every level of the plant and animal king- 
dom. One of the most striking is described in Parasitism and Degeneration 
by Jordan and Kellogg. From single-celled plants and animals to vertebrates, 
in amazing environments and through amazing metamorphoses, the para- 
sites live on others; unable to find a host, they die. 

Next we turn to the spectacle of life in individual species. Flowering Earth 
is a long, full history of the plant kingdom. Donald Culross Peattie traces 
the steps from the first single-celled life which appeared on earth, to the 
algae, the Age of Seaweeds, the first plants which grew on land, the fern 
forests, the conifers and cyeads, and finally to the modern floras. He tells us 


about the function of chlorophyll, the breathing of plants. He shows how 
even the iron deposits of Minnesota were formed by microscopic plants. 

T. H. Huxley's Lobster helps us "to see how the application of common 
sense and common logic to the obvious facts it presents, inevitably leads us 
into all the branches of zoological science." He shows us the unity of plan 
and diversity of execution which characterize all animals, whethex they swim, 
crawl, fly, swing from trees or walk the ground. 

We travel from the simplest to the highest in animal life, beginning with 
The Life of the Simplest Animals in which Jordan and Kellogg show how 
single-celled animals eat, react, reproduce. Secrets of the Ocean, at high 
and low tide, and under the waves, are disclosed for us by William Beebe, 
with sea worms, shrimps and fishes playing roles. In The Warrior Ants by 
Haskins we see many resemblances to man's own wars, much that we can 
learn about the human race. Ditmars, known for his work on snakes, and 
his assistant Grecnhall introduce us to one of the most exciting of all nat- 
uralist adventures in The Vampire Bat. (Eckstein shows us the intelligence 
of Ancestors, in apes that pull ropes arid stack boxes, that react emotionally 
like men.) 


With the great apes we have reached a stage of development which 
approaches that of man, and thinking about apes leads us inevitably to a 
consideration of Evolution. Here again is a theory that has changed our 
entire way of thinking and in Darwinisms we obtain a brief insight into the 
character of the man who originated it. Darwin and "The Origin of Species" 
by Sir Arthur Keith, points out that Darwin's masterpiece is still as fresh 
as when it was first written. Darwin recognized that variation in nature is 
the means by which natural selection can operate. How variation occurred 
he did not know. It remained for others to analyze the problem further: de 
Vries and Bateson discovered that plants and animals are subject not only to 
small variations but also to large and sudden "mutations." And as a result 
of these inherited mutations, new varieties are swiftly bred. 

It was then that biologists rediscovered the work of a forgotten Austrian 
monk. Hugo Iltis, one of his compatriots now in this country, describes 
Gregor Mendel and His Work with clarity and charm. These are the basic 
laws of modern genetics. With the discovery of the genes and the chromo- 
somes, further advances have been made. Their function is explained in 
Part Five, in You and Heredity by Amram Scheinfeld, a selection that might 
well have been included here, had its emphasis not been so strongly on man 

So much for the main evolutionary thread. But there are important by- 
ways. Julian Huxley, grandson of the great T. H. Huxley and himself a well- 
known biologist, explores one of them in The Courtship of Animals, tracing 
the influence of the theory of sexual selection on our interpretation of ani- 


mals' development and variation. In Magic Acres, Alfred Toombs describes 
amusingly the effects of the laws of heredity on plant and animal breeding. 
Use of our knowledge has made possible such experimental stations as that 
at Beltsville, Maryland, "where the hens lay colored eggs, where the tomatoes 
sprout whiskers, and the apples defy the law of gravity." 


The Nature of Life 


From The Nature of Life 


picture of the evolution of the universe which holds the imagination 
captive. Some of them believe that all kinds of matter have been evolved 
from one original substance, hydrogen, and that out of the material thus 
created solar systems were built up. They are able to give us a fairly 
satisfactory description of the processes which formed bodies like our 
earth. Their account is supplemented by the geologist, who pictures the 
progressive changes on the surface of the earth whereby it became fitted 
to support life. The fascination of these researches is heightened when 
we consider that they lead directly to a question of universal interest 
which lies in the province of the biologist, How did life make its appear- 
ance on our planet? 

To this question an answer was given long ago by Lucretius and others, 
who said that life arose out of lifeless materials. This is known as the 
doctrine of spontaneous generation. 

The adherents of this doctrine believed that life could arise from non- 
living materials whenever the conditions were favorable. For a long time 
this belief found favor with many thinkers. But the experiments of 
Pasteur and Tyndall showed that if all the living organisms in a nutrient 
solution were killed, and if it were kept free from contamination by 
germs from without, no life subsequently appeared. 

In spite of this evidence the doctrine of spontaneous generation was 
revived from time to time. One of the ablest botanists of the past genera- 
tion predicted that we should one day discover living forms too small to 
be seen by our microscopes; these, he said, represent the earlier steps in 



the evolution of living forms from lifeless matter. This prediction has 
been verified in so far as we now know a considerable number of such 
forms (filterable viruses) some of which cause important diseases. They 
cannot be detected by the ordinary microscope; they pass through filters 
which retain all the ordinary bacteria. But we do not think of them as 
lending support to the doctrine of spontaneous generation, since there 
is no proof that they can arise from lifeless material. 

How then did life originate? Are we not forced to assume that some- 
where, at some time, spontaneous generation must have taken place? 
Although no such process appears to occur at present we may neverthe- 
less suppose that in earlier geological epochs and under more favorable 
conditions it might have happened. And if, as Arrhenius supposes, life 
can originate on any appropriate heavenly body and spread thence to 
other bodies we have an immense extent of time and space in which to 
find conditions favorable to the origin of life. It may be that such condi- 
tions have never existed on our planet and perhaps have occurred but 
rarely in the history of the universe. It is not impossible, however, that 
we may learn of their occurrence, in the past or the present, since the 
spectroscope gives us accurate information about the composition of 
heavenly bodies and, in the case of distant stars, tells us what they were 
like thousands of years ago. If we do not observe on the earth the con- 
ditions necessary for the origin of life we may perhaps hope to find them 
in some of these heavenly bodies which might differ sufficiently from 
our planet to provide the necessary combination of factors. 

Arrhenius thinks that spores of bacteria might be carried to the upper 
limits of our atmosphere and thence be expelled into interstellar space, 
poetically called the "ether sea." There the spores might be driven away 
from the sun by the action of light, which might exert on such small 
bodies pressure sufficient to carry them to the outermost limits of our 
solar system. Thus interstellar space might conceivably be peopled with 
spores which could come in contact with any heavenly body that had 
reached a stage in its development at which life could be supported. 

It has been objected that the spores might be killed by intense cold, 
dryness, lack of air, or the action of light. But some spores are resistant 
to these influences and it is by no means certain that they could not 
survive a long time in interstellar space. 

The theory of Arrhenius stands out as a stimulating example of specu- 
lative thought. It is inspiring to picture life, taking flight from worlds 
outworn to fresh fields in younger planets, and persisting as long as the 
universe can harbor it, in cycle on cycle of endless progress. We may 
admire this beautiful theory as a splendid achievement of the creative 


imagination but we cannot at present prove or disprove its correctness. 
If it should one day turn out to be true? it will greatly widen the possi- 
bility of finding appropriate conditions for the origin of life. 


Leaving this riddle of the origin of life, let us turn to another question 
of equal importance. What new factor entered into the universe with the 
first appearance of life? We may perhaps put this in a more concrete 
form by asking, How may we distinguish the living from the dead? 

It may not seem very difficult to answer this question but the matter 
is less simple than might at first appear. As an illustration let us take 
some dry seeds. Their appearance does not tell us whether they are alive 
or dead. Most people if called upon to decide would plant them, and 
use growth as a test of life. 

If we are to employ growth in this manner it is important to have a 
clear understanding of what it means. Growth is often thought of as 
comprising the whole development of the organism. Ordinarily the 
life cycle of an animal or plant begins with a single cell, which by 
repeated division produces a mass of cells. The form of the organism 
then changes, and its parts become differentiated so as to perform dif- 
ferent functions. 

The question now arises, What is essential to the conception of growth ? 
A simple illustration will make it clear that growth may go on without 
cell division, change of form or color, differentiation, or assimilation of 
food. A small, spherical, green cell, desiccated by the drying up of a pool 
in which it has lived, and blown about by the wind, eventually falls into 
water. Such a cell often remains alive and when it again finds itself in 
water begins to grow. No one will deny that this is genuine growth but 
it certainly need not possess all the features which we have enumerated. 
In the first place cell division may be absent for a long time. Many cells 
increase enormously in size and never undergo division. A nerve cell 
may grow to be many hundred times its original length without divid- 
ing; and it will continue to function for years and finally die without 
any sign of nuclear or cell division. We cannot therefore regard cell 
division as essential to the conception of growth, though in most cases 
it accompanies growth and is advantageous because it provides separate 
compartments in which the diverse processes of the organism can go on 
without mutual interference. 

There may be no change of form or color in the green cell of which 
we are speaking, since it may remain green and spherical while growing. 
Nor is there any reason to suppose that in general a change of form is 


essential to growth. It commonly occurs but is by no means indispensable. 
Nor is it necessary that a differentiation of the organism into unlike parts 
should take place in order that a process may be called growth. Such 
differentiation is not observed during the growth of the simplest cells, 
such as bacteria, which may have at the beginning all the parts they 
possess when growth is complete. 

Of especial interest is the assimilation of food and the building up of 
those substances which are characteristic of each kind of organism. We 
know that seeds can grow for weeks in the dark, absorbing nothing 
except air and water. Under these circumstances the food which is stored 
in the seed steadily decreases. A kidney bean grown under such condi- 
tions may reach a height of four feet and gain in weight more than fifty 
fold. Yet this great gain in weight is wholly due to the water it absorbs. 
Its dry matter steadily decreases during the whole period, undergoing a 
process of combustion which results in continually giving off carbon 
dioxide to the air. In this way nearly half the dry material may disap- 
pear during growth. 

It is true that growth must eventually cease under these circumstances 
but the fact that it can go on for so long although the plant takes in no 
food shows that increase in dry weight is not necessary for growth. 

Since we find that growth may occur without increase in dry weight, 
change of form or color, cell division, or differentiation, we may ask, 
What is really essential to growth ? The answer seems to be, An increase 
in size due to the absorption of water. Let us now look into this more 

It is a very striking fact that when dry seeds are planted in moist soil 
the dead seeds appear to grow in the same way as the live ones during 
the first few hours. We find, however, that a dead seed soon stops 
growing while the living one continues. This suggests that the water is 
not absorbed in quite the same manner in the two cases. Absorption of 
water may occur in two ways, which are known as imbibition and 
osmosis. Imbibition is the process which occurs when a piece of dry 
wood is placed in water. The water is taken up into minute pores, other 
processes follow, and the result is a swelling which, though short-lived, 
can develop great pressure. At one time granite blocks were split open 
by drilling holes in a straight line and inserting plugs of dry wood. These 
were covered with wet rags, the wood absorbed water and the granite 
block was split. Careful measurements show that starch may develop a 
pressure of thirty thousand pounds per square inch in taking up water. 
It is therefore no wonder that a ship loaded with rice is quickly burst 
asunder if water reaches the cargo. 


In osmosis water is absorbed in a different way. This may be illustrated 
by the story of the good abbe who hid a skin of wine in the cistern of 
the abbey. When the monks developed an unusual taste for water he 
investigated and found to his horror that the skin had burst. The wine 
had taken up water through the skin because it contained substances 
which attract water (the word "attract" is here used in a somewhat 
figurative sense). In the living cell there is a protoplasmic membrane 
which corresponds to the skin, and inside this a solution which attracts 
water. As water is taken up the protoplasmic membrane is stretched, 
and if there is a cellulose wall outside the living membrane it shares the 
same fate. The living membrane can be stretched almost indefinitely 
because the cell can furnish it with new material so that it can continue 
to expand without rupture. At the same time the cell can produce 
substances which attract water. It is therefore possible for growth to 
continue indefinitely. 

The growth of the dead seed is due to imbibition while that of the 
living seed is due during the first few hours principally to imbibition, 
after that principally to osmosis. We should therefore expect that the 
dead seed would soon stop growing while the living one would continue. 

Osmosis does not ordinarily develop so much pressure as imbibition but 
it is supposed that the pressure it produces in the living cell may reach 
three hundred pounds per square inch or even more: this is as much as 
is commonly found in steam boilers. It is sufficient to drive ferns up 
through macadamized roads and concrete sidewalks and to enable toad- 
stools to lift heavy flagstones. 

Let us now consider whether there is anything in growth which can 
be used as a criterion of life. We have tried first of all to discover what 
is essential to growth. Such things as cell division, change of form, dif- 
ferentiation, and the assimilation of food may be taken away, and yet 
growth may go on for a long time. One process cannot be dispensed with, 
the absorption of water. This appears to be the essential thing. 

If growth consists of the absorption of water can this serve as a test 
to distinguish the living from the dead? As we have seen, absorption 
of water takes place by imbibition or by osmosis. Imbibition cannot 
serve as a mark of distinction for it goes on in the same way in dead and 
in living seeds. If we are to employ growth as a test of life it can be only 
on the ground that osmosis is in some way peculiarly characteristic of 
living cells. Let us see whether this is the case. 

One way of attacking this question is to attempt to make an artificial 
cell which will act like the living. We may employ for this purpose two 
solutions, A and 5, such that a drop of A introduced into a vessel con- 


taining B will react with it and form a membrane which is impervious 
to both A and B, but is permeable to water. We have now what we may 
for convenience call an artificial cell. It consists of a membrane in the 
form of a rounded sack which completely incloses a drop of the solution 
A and which is surrounded by the solution B. If now solution A is more 
concentrated than solution B water will be attracted by solution A and 
will pass into the artificial cell which in consequence will expand and 
stretch the membrane. Under the proper experimental conditions this 
may continue for a long time. 

We may employ for such experiments a great variety of materials, as 
copper salts in a solution of potassium ferrocyanide, metallic salts of 
various kinds in a solution of water glass, or tannic acid in a solution 
of gelatin. In some cases the artificial membrane expands by repeated 
rupture and repair, in others it is steadily stretched without rupture, and 
at the same time strengthened by the deposit of new material. The 
protoplasmic membrane might conceivably expand in either way. It is 
not certain which method is followed. 

In both the living and the artificial cell growth is quickened by increase 
of temperature. In the living cell there is an upper limit of temperature 
beyond which no growth takes place. This seems to be due to the proteins 
of the living cell. If we could employ such proteins in the membrane of 
the artificial cell we might obtain a similar result. 

The rate of growth depends, in the living as in the artificial cell on 
the supply of substances within the membrane which can attract water. 
In the case of the living cell these are mostly sugars, organic acids, salts, 
and so on, and we can employ these same substances in the artificial 
cell. In the living cell we often find starch, which takes little part in 
attracting water but which may be gradually transformed into sugar 
which attracts water actively. In the same way we may place starch in 
the artificial cell and have it slowly transformed to sugar and thereby 
cause the cell to take up water. 

If the artificial cell is placed in a solution which is more concentrated 
than that inside the cell, water is attracted from the cell to the outside 
solution and in consequence the cell shrinks. This is also true of the living 
cell. If it is growing in tap water it can be made to shrink by putting 
it into a sugar solution which withdraws water. If replaced in water it 
again expands. Since we regard this as growth, the shrinkage may be 
looked upon as the reversal of growth. We find that many living cells 
may be made to grow and shrink several times in succession, just as in 
the case of the artificial cell. 

If the outside solution is concentrated enough to draw water out of 


the cell it may nevertheless prevent water from going in and so check 
growth in proportion to its concentration. Consequently by varying the 
concentration we may accurately control the rate of growth. 

We might go on to discuss other points of resemblance between the 
growth of the living and the artificial cell but this hardly seems neces- 
sary. If we accept the definition of growth given above it is clear that 
the artificial cell furnishes an imitation which is sufficiently complete for 
our purpose. We must therefore conclude that there is nothing in the 
absorption of water by the living cell, either by imbibition or by osmosis, 
which differs essentially from these processes as found in non-living 

In conclusion we may ask whether life can go on in the absence of 
growth. We know that certain things may be temporarily taken away 
from living matter without taking away life itself. Is growth one of 
these? Certainly the resting seed lives for years without any sign of 
growth. This is also true of many animal cells. The suppression of all 
signs of growth does not in any way involve the suppression of life. 
Even when placed in moist soil with all external conditions favorable 
some living seeds remain quiescent for months or years before they start 
to grow. 

Hence it seems possible to have life without growth and growth with- 
out life. 

Our analysis of the process of growth illustrates the method which 
biological investigation must very commonly pursue. The biologist wishes 
to study living matter in the same manner that the chemist and physicist 
study their material. His first task is observation, after that he must 
analyze in order to discover what properties are essential and what are 
merely accompanying phenomena. He need not attempt to explain these 
phenomena, for, after all, we can never arrive at ultimate explanations. 
But he can attempt to predict and control. The physicist cannot explain 
electricity but he can predict and control electrical phenomena. In the 
same way the biologist hopes to be able to predict, and control life 
phenomena. One method which he finds particularly useful is to make 
artificial imitations which closely resemble the phenomena he is studying. 
If he succeeds in this he may find the fundamental laws of physics and 
chemistry on which life phenomena are based. 


The Characteristics of Organisms 


From Life: Outlines of General Biology 

apartness of living creatures from non-living things seems con- 
spicuous. It appears almost self-evident that an organism is something 
more than a mechanism. But when we inquire into the basis of this 
common conviction we usually find that the plain man is thinking of the 
highest animals, such as horses and dogs, in which he recognises incipient 
personalities, in a world quite different, he says, from that of machines, 
or from that of the stars or stones. His conviction rests on his recognition 
of them as kindred in spirit; but he hesitates when we ask him to consider 
the lower animals, down to corals and sponges, and still more when 
we ask what he thinks about plants. In such relatively simple organisms 
as corals and seaweeds, he detects no mental aspect; and apart from this, 
they show him but little of that bustling activity which is part of his 
picture of what "being alive" means. Thus, while he was sure that dog 
and wheelbarrow were separated by a great gulf, he is not so convinced 
about the difference between a coral and a stone. It is, therefore, for the 
biologist to explain as clearly as he can the fundamental characteristics of 
all living creatures. . . . 


The symbol of the organism is the burning bush of old; it is all afire, 
<iut it is not consumed. The peculiarity is not that the organism is in 
continual flux, for chemical change is the rule of the world; the charac- 
teristic feature is that the changes in the organism are so regulated 
that the integrity of the system is sustained for a longer or shorter 
period. That excellent physiologist, Sir Michael Foster, used to say that 
"a living body is a vortex of chemical and molecular change"; and the 



image of a vortex expresses the fundamental fact of persistence, in spite 
of continual flux. 

Here it is fitting to quote one of the cfassic passages in modern bio- 
logical literature, what Huxley said of the vital vortex in his Crayfish 
(1880, p. 84): 

"The parallel between a whirlpool in a stream and a living being, 
which has often been drawn, is as just as it is striking. The whirlpool is 
permanent, but the particles of water which constitute it are incessantly 
changing. Those which enter it, on the one side, are whirled around and 
temporarily constitute a part of its individuality; and as they leave it on 
the other side, their places are made good by new-comers. . . . 

"Now, with all our appliances, we cannot get within a good many 
miles, so to speak, of the crayfish. If we could, we should see that it was 
nothing but the constant form of a similar turmoil of material molecules 
which are constantly flowing into the animal on the one side, and 
streaming out on the other." 

The comparison has great force and utility; it vivifies the fundamental 
fact that streams of matter and energy, such as food and light, are 
continually passing into the organism, and that other streams are con- 
tinually passing out, for instance in the form of carbon dioxide and 
heat. On the other hand, the comparison has its weakness and possible 
fallaciousness; for it is too simple. It does not do justice to the character- 
istic way in which the organism-whirlpool acts on the stream which is 
its environment; it does not do justice to the characteristic way in which 
the organism-whirlpool gives rise to others like itself. No one who believes 
that higher animals (at least) have a mental aspect that counts, can 
agree that the organism is exhaustively described as "nothing but the 
constant form of a turmoil of material molecules." And even if the 
mental aspect be ignored, there remains as a fundamental characteristic 
that the "constant form" is secured by organic regulation from within. 
Life is nothing if not regulative. 

Biology has come nearer the crayfish since Huxley's day, and it is 
profitable to linger over the fact that the living creature persists in spite of 
its ceaseless change. As a matter of fact it persists because of the self- 
repairing nature of its ceaseless change. Hence we give prominence to 
this material flux. 

METABOLISM OF PROTEINS. Proteins are nitrogenous carbon-compounds 
that are present in all organisms, and, apart from water, of which 
there is seldom less than 70 per cent., they constitute the chief mass of 
the living substance. They are intricate compounds, with large mole- 


cules, which are built up of groups of amino-acids, i. e. fatty acids in 
which one of the hydrogen atoms is replaced by the ammo-group NHs 
Proteins, such as white of egg, or the casein of cheese, or the gluten of 
wheat, do not readily diffuse through membranes; they occur, as will 
be afterwards explained, in a colloid state, and although some, e. g. 
haemoglobin, the red pigment of the blood, are crystallisable, they are 
not known in a crystalloid state in the living body. Though relatively 
stable bodies, proteins are continually breaking down and being built 
up again within the cells of the body, partly under the direct influence 
of ferments' or enzymes. 

There are constructive, synthetic, upbuilding, or winding-up chemical 
processes always going on in the living organism, which are conveniently 
summed up in the word anabolism, applicable, of course, to the synthesis 
of other carbon-compounds besides proteins, notably to the formation 
of carbohydrates in the sunned green leaf. There are also disruptive, 
analytic, down-breaking, running-down chemical processes always going 
on in the living organism, which are conveniently summed up in the 
word \atabolism applicable, of course, to other carbon-compounds be- 
sides proteins, as, for example, to the breaking down of amino-acids into 
fatty acids and ammonia. To include the two sets of processes, anabolism 
and katabolism, the general term metabolism is used. It is convenient to 
use this term in a broad way, as the equivalent of the German word 
"Stoffwechsel" (change of stuff), to include all the chemical routine of 
the living body. The present point is that living always involves the 
metabolism of proteins; and that this is so regulated that the living 
creature lives on from day to day, or from year to year, even from century 
to century. 

There is intense activity of a simple kind when the fragment of 
potassium rushes about on the surface of the basin of water, but it differs 
markedly from the activity of the Whirligig Beetle (Gyrinus) that 
swims swiftly to and fro, up and down in the pool. The difference is 
not merely that the chemical reactions in the beetle are much more in- 
tricate than is the case with the potassium, and that they involve 
eventually the down-breaking and up-building of protein molecules. 
The big difference is that the potassium fragment soon flares all its 
activity away and changes into something else, whereas the beetle retains 
its integrity and lasts. It may be said, indeed, that it is only a difference 
in time, for the beetle eventually dies. But this is to miss the point. The 
peculiarity we are emphasising is that for certain variable periods the 
processes of winding-up in organisms more than compensate for the 
processes of running down. A primitive living creature was not worthy 


of the name until it could balance its accounts for some little time, 
until it could in some measure counter its katabolism by its anabolism. 
Perhaps it was only a creature of a day, which died in the chill of 
its first night, probably after reproducing its kind; but the point 
is that during its short life it was not like a glorified potassium 
fragment or a clock running down. It was to some extent winding itself 
up as well as letting itself run down. It was making ends meet 

In the immense furnaces of the stars, with unthinkably high tem- 
peratures, it may be that hydrogen is being lifted up into more complex 
forms of matter, but on the earth all the chemico-physical clocks are 
running down. . . . 

In the little corner of the universe where we move, we are living 
in a time of the running down of chemico-physical clocks. But the 
characteristic of living organisms is that they wind themselves up. . . . 

COLLOIDAL PROTOPLASM. The accumulation of energy in organisms 
is mainly effected by storing complex chemical substances, not merely as 
reserves in the ordinary sense, like the plant's starch and the animal's fat, 
but in the living substance itself in the form of increased protein material. 
The chemical formula of egg-albumin, to take a familiar protein, is often 
given as Ci428H2244N364O4G2Si4; and this hints at the complexity of 
these substances. In the strict sense, protein material does not form 
definite stores in animals, though it is a common reserve in the seeds of 
plants, but it accumulates as the amount of living matter increases. The 
potential chemical energy of the complex carbon-compounds found in 
living cells is particularly valuable because the living matter occurs in a 
colloidal state. Of this it is enough to say that a watery "solution" holds 
in suspension innumerable complex particles, too small to be seen, even 
with the microscope, but large enough to have an appreciable surface. 
The particles do not clump together or sink because each carries an 
electric charge, and like charges repel one another. . . . 

SPECIFICITY. Each kind of organism has its chemical individuality, 
implying a specific molecular structure in some of the important constit- 
uents, and a corresponding routine of reactions. This is particularly true 
of the proteins, and there are probably special proteins for each genus 
at least. There is chemical specificity in the milk of nearly related 
mammals, such as sheep and goats; and, as Gautier showed in detail, in 
the grape-juices of nearly related vines. A stain due to the blood of a 
rabbit can be readily distinguished from a stain due to the blood of a 
fowl or of a man. More than that, as Reichert and Brown have demon- 
strated conclusively (1909), the blood of a horse can be distinguished from 


that of an ass. The crystals of the haemoglobin or red blood pigment of a 
dog differ from those of a wolf, from which the dog evolved, and 
even from those of the Australian dingo, which seems to be the result 
of domesticated dogs going wild and feral. Even the sexes may be 
distinguished by their blood, and there are two or three cases among 
insects where the colour of the male's blood is different from the 
female's. The familiar fact that some men cannot eat particular kinds of 
food, such as eggs, without more or less serious symptoms, is a vivid 
illustration of specificity. It looks as if a man was individual not merely 
in his finger-prints, but as to his chemical molecules. Every man is 
his own laboratory. Modern investigation brings us back to the old 
saying: "All flesh is not the same flesh; but there is one kind of flesh of 
men, another flesh of beasts, another of fishes and another of birds." . . . 
To some who have not looked into the matter it may seem almost 
preposterous to speak of a particular protein for every genus at least. 
But the work of Emil Fischer and others has shown that there is incon- 
ceivable variety in the groupings and proportional representations of the 
twenty-odd amino-acids and diamino-acids which constitute in varied 
linkages the complex protein molecules. There must be a million million 
possibilities and more. As there are about 25,000 named and known 
species of Vertebrates and about 250,000 (some would say 500,000) 
named and known species of Invertebrates, there may readily be 
particular proteins for every species of animal, leaving plenty to spare 
for all the plants. 


The organism's power of absorbing energy acceleratively, and of ac- 
cumulating it beyond its immediate needs, suggests another triad of 
qualities growing, reproducing, and developing, which may be profit- 
ably considered together. . . . 

GROWTH. The power of growth must be taken as a fundamental 
characteristic of organisms, for it cannot as yet be re-described in 
chemical and physical terms. The word is a convenient label for a 
variety of processes which lead to an increase in the amount of living 
matter, and while there are chemical and physical factors involved in 
these processes, we are bound in the present state of science to admit 
that growth depends on the veiled tactics of life. Its results are extraor- 
dinary achievements, which would be astounding if they were not 
so familiar. From a microscopic egg-cell there develops an embryo-plant 
which may grow, say, into a Californian "Big Tree" perhaps three 
hundred feet in height and over three thousand years old. A frog is 


about three or four inches in length, its egg-cell is under a tenth of an 
inch in diameter; "the mass of the human adult is fifteen billion times 
that of the human ovum." In the strict sense growth means an increase 
in the amount of the organism's living matter or protoplasm, but it 
is often associated, as in a cucumber, with great accumulation of water; 
or, as in the case of bone, with the formation of much in the way of 
non-living walls around the living cells. . . . 

The indispensable condition of growth is that income be greater than 
expenditure. A variable amount of the food-income is used to meet 
the everyday expenses of living; the surplus is available for growth; and 
this must be understood as including, besides increase in size, that im- 
perceptible growth which brings about the replacement of worn-out 
cells by fresh ones. Green plants are great growers when compared with 
animals the Giant Bamboo may grow a foot in a day and that is 
mainly because they get food-materials at a low chemical level, that is 
to say from the air and the soil-water. Helped by its chlorophyll, the 
green plant is able to use part of the energy of the sunlight that bathes 
its leaves to build up sugars, starch, and proteins, first of course for 
its own maintenance and for its growth, thereafter for "reserves," vari- 
ously stored for its own future, or that of its offspring. On this highly 
profitable synthesis and storage in the plant, the growth of all animals 
depends directly in the case of the sheep and other herbivores, in- 
directly in the case of the tiger and other carnivores. 

Food is thus obviously an indispensable condition of growth; but 
there are some puzzling cases, e. g. the striking growth behaviour of 
a single fragment of Planarian worm, without food-canal, and thus in- 
capable of ingesting food; yet soon growing a new head and posterior 
end, fashioning itself anew into a perfect miniature worm. Here, as in a 
germinating seed, there must have been absorption of water and utilisation 
of the previous material in a less condensed form. 

Another curious form of growth is expressed in the replacement of 
lost parts, such as the claw of a crab, or the arm of a starfish; and here 
again the body yields supplies. One of the most extraordinary instances 
of such replacement-growth is that seen annually when the stag, having 
dropped his antlers, rapidly grows a new set, which, in the monarch, 
may weigh seventy pounds! 

The great majority of animals have a definite limit of growth, 
an optimum size, which is normally attained by the adult and rarely 
exceeded; so there must be some method of growth-regulation. On the 
other hand, some fishes and reptiles continue growing as long as they 


live, just like many trees; and this shows that a limit of size is not 
fundamentally insisted on by nature. 

When we think of giants and dwarfs, and of the rarity of their 
occurrence, the idea of regulation is again suggested. So also when we 
observe the occurrence yet rare occurrence of monstrous growths 
among animals, we see that growth is essentially a regulated increase in 
the amount of adjustment of living matter. By what means is such 
regulation affected? The modern answer to this question is twofold. 
Regulation is partly due to certain hormones (chemical "messengers") 
which are produced in "ductless glands" and distributed by the blood. 
Thus the hormones of the thyroid gland, and those of the pituitary body, 
have, among other functions, that of growth-control. Again, it has 
been shown that parts where metabolism is most intense, e. g. the 
growing point of a stem, exert a sway or dominance over the growth 
of other parts, as we shall see more fully later. 

Another feature of growth is its periodicity. All are familiar with the 
rings of growth on the cut stem of a tree, which mark its years, through 
the well-marked seasonal alternation of spring and summer wood, which 
are different in texture. This instance is no exceptional case, but a 
vivid illustration of the rhythmic periodicity of life. The same is seen 
in the zoning of fish-scales and the barring of birds' feathers, and in the 
familiar growth-lines on the shells of the seashore. 

Familiarity is apt to dull our eyes to the marvel of growth the 
annual covering of the brown earth with verdure; the desert blossoming 
as the rose; the spreading of the green veil over the miles of wood- 
land; the bamboo rising so quickly that one can see it grow; the Sequoia 
or Big Tree continuing to increase in bulk for three thousand years; the 
coral-polyps adding chalice to chalice till they form a breakwater a 
thousand miles long; the Arctic jellyfish becoming bigger and bigger 
till the disc is over seven feet in diameter and the tentacles trail in 
the waves for over a hundred feet. Again, many an animal egg-cell 
develops into a body that weighs billions of times as much as its 
beginning; and this is far exceeded in the growing up of giants like 
a Blue Whale, eighty-five feet in length, or an Atlantosaurus with a 
thigh-bone as high as a tall man. 

MULTIPLICATION. The corollary of growth is multiplication, a term 
that we are using here in preference to the more general word repro- 
duction, which includes the whole series of functions concerned with 
giving rise to other organisms. Multiplication essentially means separating 
off portions or buds, spores or germ-cells, which start a new generation. 
In the asexual method of separating off large pieces, the connection 


with growth is obvious; multiplication occurs as a consequence of 
instabilities which follow overgrowth. As Haeckel said long ago, repro- 
duction is discontinuous growth. Its externally simplest form is seen in 
the division of an overgrown unicellular organism, yet in the everyday 
division of most of the cells of plants and animals, this has been elabo- 
rated into an intricate process, which secures that each of the two 
daughter-cells gets a meticulously precise half of everything that is in 
the parent-cell. 

The connection between growth and cell-division is not far to seek. 
Spencer, Leuckart, and James pointed out independently that as a cell 
of regular shape increases in volume, it does not proportionately increase 
in surface. If it be a sphere, the volume of cell-substance or cytoplasm to 
be kept alive increases as the cube of the radius, while the surface, 
through which the keeping alive is effected, by various processes of 
diffusion, increases only as the square. Thus there tends to set in a 
hazardous disproportion between volume and surface, and this may set 
up instability. The disturbed balance is normally restored by the cell 
dividing into two cells. . . . 

In cases of sexual reproduction, where germ-cells are separated off to 
start a new generation, the relation between growth and multiplication 
is not, of course, so direct as in cases of asexual reproduction by fission or 
fragmentation. It may be pointed out that reproduction often occurs at 
the limit of growth, and that there is a familiar seesaw between feeding 
and breeding periods, between leafing and flowering, between nutrition 
and reproduction. 

The division of a cell is one of the wonders of the world. Bateson 
wrote: "I know nothing which to a man well trained in scientific 
knowledge and method brings so vivid a realisation of our ignorance of 
the nature of life as the mystery of cell-division. ... It is this power of 
spontaneous division which most sharply distinguishes the living from 
the non-living. . . . The greatest advance I can conceive in biology 
would be the discovery of the instability which leads to the continued 
division of the cell. When I look at a dividing cell I feel as an astronomer 
might do if he beheld the formation of a double star: that an original 
act of creation is taking place before me." 

In the present youthful condition of biology it is wise to return 
at frequent intervals to concrete illustrations. We need the warmth of 
actual facts to help us to appreciate the quality of reproductivity which 
we are only beginning to understand. In one day the multiplication of 
a microbe may result in a number with thirty figures. Were there an 
annual plant with only two seeds, it could be represented by over a 


million in the twenty-first year. But a common British weed (Sisymbrium 
officinal?) has often three-quarters of a million of seeds, so that in 
three years it could theoretically cover the whole earth. Huxley calculated 
that if the descendants of a single green-fly all survived and multiplied, 
they would, at the end of the first summer, weigh down the population 
of China. A codfish is said to produce two million eggs, a conger eel ten 
millions, an oyster twenty-millions. The starfish Luidia, according to 
Mortensen, produces two hundred million eggs every year of its life. 

DEVELOPMENT. In active tissues, like muscle or gland, wear and 
tear is inevitable, especially in the less labile parts of the cells the 
furnishings of life's laboratories, such as the for the most part ultra- 
microscopic films that partition the cyptoplasm into areas. When the 
results of the wear and tear over-accumulate, they tend to depress 
activity and in time to inhibit it; and this means ageing, towards death. 
But this decline of vitality may be counteracted by rejuvenescence- 
processes in the ageing cells, or by the replacement of worn-out cells by 
new ones. In some cases the hard-worked cells go fatally out of gear, 
as in the brain of the busy summer-bee, which does not usually survive 
for more than six or eight weeks. In other cases, as in ordinary muscle, 
the recuperation afforded by food and rest is very perfect, and the same 
cell may continue active for many years. Such cells are comparable to 
the relatively simple unicellular animals, like the amoebae, which recuper- 
ate so thoroughly that they evade natural death altogether. In another 
set of cases, e. g. the lining cells of the stomach, or the epithelium 
covering the lips, the senescent cells die and drop off, but are replaced by 
others. The outer epidermic layer of the skin (the stratum corneum) is 
continually wearing away, and as continually being replaced by con- 
tributions from the more intensely living and growing deeper stratum 
(the stratum Malpighii). Similarly at the tip of a rootlet there is a 
cap of cells which are always dying away and being replaced from the 
delicate growing point which they protect. From such replacement of cells 
there is an easy transition to the re-growth of lost parts. The starfish 
re-grows its lost arm, the crab its claw, the snail its horn, the earthworm 
its head. From cells below the plane of separation there is in each 
case a regulated growth, which replaces what has been lost. We have 
already mentioned a very striking instance, in which regrowth is normal, 
and in organic and seasonal rhythm independent of any violence from 
without namely, the re-growth which gives the stag new antlers to 
replace those of the previous year. . . . The needful renewal of 
embryonic tissue is rarely seen, unless there be some recurrent need for it. 
Most lizards can re-grow their long tail if that has been snapped off by a 


bird or surrendered in fear or in battle, but the chameleon which keeps 
its tail coiled round the branch, has not unnaturally lost this power. 
Long-limbed animals like crabs, and starfishes with their lank arms, 
have great regenerative capacity, in striking contrast to the compact 
and swiftly moving fishes, which cannot even replace a lost scale! The 
recurrence of non-fatal injuries is not common among the higher 
animals, so their power of regenerating important parts has waned. 
Enough of this, however; our present point is that the regeneration of 
lost parts illustrates a renewal of that regulated growth of complicated 
structure which is characteristic of embryonic development. Out of 
apparently simple cells at the stump of a snail's horn, the whole can be 
regrown, including the eye at the tip; and this may occur not once only, 
but forty times. From the broken portion of a Begonia leaf there buds a 
complete plant to root and shoot and flower. From such reconstruc- 
tion there is but a step to the asexual multiplication of many plants and 
animals whether by the bulbils of the lily, the budding of the hydra 
in the pond, or the halving of the Planarian worm. When the tail-half 
of the dividing Planarian worm proceeds to differentiate a new head, 
with brain-ganglia, eyes, and mouth complete, there is an obvious 
development the formation of new and complex structures out of the 
undifferentiated and apparently simple. . . . 

In his discussions of the characteristics of living creatures, Huxley was 
wont to lay emphasis on what he called "cyclical development." Within 
the embryo-sac, within the ovule, within the ovary of the flower, a 
miniature plant is formed by the division and re-division of the 
fertilised egg-cell. The ovule becomes a seed; and this, when sown, 
a seedling. By insensible steps there is fashioned a large and varied 
fabric, of root and shoot, of leaves and flowers. But sooner or later, after 
this development is complete, the grass begins to wither and the flower 
thereof to fade. In the case of an annual plant, there is soon nothing 
left but the seeds, which begin the cycle anew. . . . 

Among animals the egg-cell, in many cases microscopic, divides and 
redivides, and an embryo is built up. Division of labour sets in among 
its units. . . . Some cells become nervous, others muscular, others 
glandular, others skeletal; and so the differentiating process continues. 
Hereditary contributions from parents and ancestors find expression, 
some of fundamental importance and others relatively trivial; the past 
lives on in the present; often the individual shows, in varying degree, 
evidence that it is "climbing up its own genealogical tree." Sometimes the 
embryo develops steadily and directly into the likeness of its kind, as 
in birds and mammals, with only traces of circuitousness, such as 


notochord and gill<lefts disclose tell-tale evidence of the lien the past 
continues to hold on the present. . . . 


A third triad of qualities which are distinctive of the living organisms 
may be summed up in the words behaviour, registration, and evolution, 
in which as in previous triads an underlying unity may perhaps be dis- 

BEHAVIOUR. Herbert Spencer spoke of life as "effective response," 
and from the amoeba upwards we recognize among animals the power 
of linking actions in a chain so that the result is behaviour always 
purposive and in the higher reaches purposeful. Responses are common 
in the inorganic world from gentle weathering to volcanic explosion 
but non-living things do not show the living creature's power of 
reacting in a self-preservative way. Among plants, for various reasons, 
such as the fixed habit of the great majority and the enclosing of the 
cells in cellulose, there is relatively little exhibition of that purposive 
"doing of things" which we call behaviour, but we must not forget the 
insurgent activities of climbing plants or the carnivorous adventures 
of Venus's Fly-trap and the Sundew. 

ENREGISTRATION. A bar of iron is never quite the same after it has 
been severely jarred; the "fatigue of metals" is one of the serious risks of 
engineering; the violin suffers from mishandling. But these are hardly 
more than vague analogies of the distinctive power that living creatures 
have of enregistering the results of their experience, of establishing 
internal rhythms, of forming habits, and of remembering. As W. K. 
Clifford put it: "It is the peculiarity of living things not merely that 
they change under the influence of surrounding circumstances, but that 
any change which takes place in them is not lost, but retained, and, as it 
were, built into the organism, to serve as the foundation for future 
action." ... In various forms this is a distinctive feature of the 
living creature. 

EVOLUTION. In the attempt to understand organisms we must en- 
visage them as a whole, we must see them in the light of evolution. 
Thus it must be recognized as characteristic of organisms that they 
give origin to what is new; they have evolved and evolution is going 
on. There is variability in the crystalline forms which the same substance 
may assume; the modern physicist tells us of "isotopes" like the different 
kinds of "lead," which have the same chemical properties, yet differ in 
the structure of the nucleus of their atoms; the modern chemist even 
assures us of the transmutation of elements, thus not a little justifying the 


medieval alchemist's dream and quest. . . . Yet these are only suggestive 
analogies; for the living organism is the supreme, though uncon- 
scious, creative chemist. 

No doubt there are species that show nowadays little or no variation; 
there are conservative living types that seem to have remained the same 
since their remains were first buried in the mud millions of years ago, 
but the larger fact is variability. In multitudes of cases the offspring show 
something new. 

What impressions of variability we get at a "show" whether of dogs 
or pigeons, roses or pansies! Here we have, as it were, the fountain of life 
rising high in the air blown into strange forms by the breeze, yet modu- 
lated, to its own ceaseless waxings and wanings, by varying pressures 
from its source. Two hundred different "forms" or varieties are described 
by Jordan in one of the commonest of small Crucifers, the whitlow-grass 
or Draba verna\ and these are no longer fluctuating but breeding true. 
Again, Lotsy speaks of the bewildering diversity exhibited by a series of 
about two hundred specimens of the Common Buzzard (Buteo buteol) 
in the Leyden Museum, "hardly two of which are alike." . . . 


Our discussions of living creatures are apt to be too abstract and cold; 
we lose the feeling of the mysterious which all life should suggest. In 
our inhibiting conventionality we run the risk of false simplification. 
Therefore, at the risk of a little repetition, we devote the rest of this dis- 
cussion to what might be called "glimpses of life" the contrast between 
the living creature and a crystal, the quality of vital insurgence, the fact 
of organic beauty. 

CRYSTALS AND ORGANISMS. When Linnaeus wrote his famous, yet now 
partly outworn, aphorism, "Stones grow; Plants grow and live; Ani- 
mals grow and live and feel," he must have been thinking of crystals. 
For ordinary stones do not grow except smaller; whereas crystals afford 
beautiful illustrations of increase in size. Suppose, says Sir William Bragg 
in his luminous lectures "Concerning the Nature of Things" (1925), 
the crystallographer wishes to get a fine big crystal of common salt, he 
suspends a minute, well-formed crystal in a solution of brine at a 
concentration just ready to form a salt precipitate. That is step one. He 
also makes sure of a certain temperature, which he knows from previous 
experience to be suitable to tempt the atoms of sodium and chlorine to give 
up their freedom "when they meet an assemblage of atoms already in per- 
fect array that is to say when they come across a suspended crystal." 
Sometimes the solution is kept in gentle movement so that various parts 


of it get a chance of meeting the nucleus, which, so to speak, tempts them 
to settle down freezing into architecture. Into the physics of this we 
need not here enter; our point is simply that in a suitable environment, 
with time and quiet, a crystal-unit "grows." By accretion it becomes a 
handsome large crystal. Onto its faces other crystal-units are added, and 
on the new faces more again, until there is formed an edifice. . . . 

The crystal increases in size in an orderly way; how does this differ 
from the growth of an animal or a plant? Is there a real resemblance, or 
is it a misleading analogy? The first answer is that a crystal increases in 
size at the expense of material, usually a solution, that is chemically the 
same as itself; whereas animals and plants feed on substances different 
from their own living matter often very different. This is sound com- 
monsense, and yet the edge is taken off it a little by two facts, first that 
it is possible to feed an amoeba on amoebae, or a tadpole on tadpoles, or q 
rat on rats; and, secondly, it is possible to increase the size of a crystal 
when it is placed in a solution of a chemically different substance, which 
has, however, the same form of crystallisation. 

Then one might lay emphasis on the fact that the increase in the size 
and weight of a crystal is by accretion from without, whereas organisms 
grow by taking in raw materials, altering these, and building from 
within. . . . 

But there is another, more general, way of looking at the difference 
between crystal increase and organic growth: the one is passive and the 
other is active. It is not so much that the crystal grows, as that it is added 
to by other crystal units usually, moreover, in saturated solution. But an 
organism actively takes in its food, actively changes and distributes it, 
and actively builds with it. 

But some authorities who press the analogy between crystals and crea- 
tures bring forward another supposed resemblance. If a crystal is broken 
there is a neat mending, provided there is the proper environment. There 
is more rapid accretion at the broken surface than elsewhere; the repair is 
often in proportion. This is very suggestive of the way in which an animal 
or a plant replaces a lost part or repairs an injury. If a crystal be broken 
into two, each half may form a perfect whole. If a Planarian worm or a 
Hydra be cut across, each half usually "regenerates" an entire animal. 
But the crystal's "regeneration" is passive, from without, and homo- 
geneous; that of the organism is active, from within, and heterogeneous. 

Another supposed resemblance that has been emphasised is the power 
of lying latent that may be seen in crystal and creature alike. The seed of a 
plant may remain dry for a decennium, but sow it and it will germinate. 
The egg or the half-developed embryo of an animal may lie unchanged 


for many years, but give it the appropriate environment and it will resume 
its activity. Entire animals like "vinegar-eels" may remain without hint of 
life for many years; but it is only necessary to put them in their proper 
surroundings to see them revive and multiply. Everyone knows how the 
spores of microbes may lie low for a long time and be blown about by the 
wind, but let one light on a suitable medium and it reasserts its power 
perhaps its virulence to our undoing. 

Now it is a similar power of lying latent that enthusiasts claim for 
crystals. Thus Dr. A. E. H. Tutton, one of the leading authorities, says: 
The virility of a crystal is unchanged and permanent. He pictures very 
vividly what may happen to a crystal of quartz detached by the weather- 
ing of a piece of granite thousands of years ago. It may be "subsequently 
knocked about the world as a rounded sand grain, blown over deserts by 
the wind, its corners rounded off by rude contact with its fellows and 
subjected to every variety of rough treatment." But if it happen in our own 
day to "find itself in water containing in solution a small amount of the 
material of which quartz is composed, silicon-dioxide, it will begin to 
sprout and grow again." From a grain of sand in such conditions several 
typical crystals of quartz may grow out in different directions. "This 
marvellously everlasting power possessed by a crystal, of silent imper- 
ceptible growth, is one of the strangest functions of solid matter, and one 
of the fundamental facts of science which is rarely realised, compared with 
many of the more obvious phenomena of nature." 

But Dr. Tutton chose a very resistant crystal; what he says of the crystal 
of quartz would not be so true of a crystal of common salt, just as what 
we said of the vinegar thread worm woufd not hold for the earthworm. 
When atoms are very firmly locked together in an intricate space-lattice 
system we do not expect them to be changeful. It is not easy to induce a 
diamond to change its state. But the persistence of some organisms through 
years of latent life is much more remarkable, for they often become dry 
and brittle, and thus pass out of the colloidal state which is characteristic 
of living matter. Yet they do not die. As for the prolonged persistence 
of some organisms when they are not in a latent state, the marvel there 
is that they retain their intact integrity in spite of the ceaseless internal 
bustle of metabolism. Plus fa change, plus c'est la meme chose. 

It is certainly a noteworthy fact that many kinds of crystals, not larger 
than bacteria, float about in the air as microbes do. And just as a microbe 
may set up a far-reaching change when it lights on a suitable medium, so 
a microscopic crystal landing in a solution which is in a properly receptive 
condition may set up crystallisation. But the differences seem to us to be 
greater than the resemblances; for the minute crystal is but a passive peg 


to which molecules attach themselves, while the microbe is an active agent 
that attacks the medium and fills it with its progeny. 

No one wishes to think of living creatures as if they had not antecedents 
in the non-living world. Science is not partial to Melchizedeks. On the 
other hand, we hold to the apartness and uniqueness of life. Dr. A. E. H. 
Tutton begins his fine book on The Natural History of Crystals (London, 
1924), by saying that no definition of life has yet been advanced that will 
not apply equally well to crystals, but we have given reasons for not accept- 
ing this statement. The living creature's growth, repair, and reproduction 
are very different from those of crystals; life is an enduring activity, 
persisting in spite of its metabolism; the organism enregisters its experience 
and acts on its environment; it is a masterful, even creative, agency. The 
crystal, especially the gem, is a new synthesis, compared with the disarray 
of the dust; the organism is another and on a different line. 

THE INSURGENCE OF LIFE. It is difficult to find the fit word to de- 
note the quality of irrepressibility and unconquerability which is char- 
acteristic of many living creatures. There are some, no doubt, that 
drift along, but it is much more characteristic to go against the stream. 
Life sometimes strikes one as a tender plant, a flickering flame; and 
who can forget that one of the Ephemerides or mayflies has an aerial 
life of but a single hour! At other times, the impression we get is just 
the opposite, for the living creature often shows itself tenacious, tough, 
and dogged. In his admirable Introduction to the Study of Trees (Home 
Univ. Library, 1927), Dr. Macgregor Skene of Bristol University men- 
tions that three carefully measured stumps of the "big tree," Sequoia 
gigantea, of California showed rings going back to 1,087, 1,122, and 1,305 
years B.C. The actual record for the second tree was 2,996 years and for 
the third 3,197, without allowing for some rings that have been lost in 
the centre. A specimen of the dragon-tree on Teneriffe is supposed to be 
6,000 years old, and a bald cypress near Oaxaca in Mexico, no feet high 
with a circumference of 107 feet at breast height, is credited with over 
6,000 years. As these giants are still standing, their longevity is inferred, 
whereas that of the felled Sequoias is proved by the ring counts. But, 
in any case, there is astounding tenacity of life, and, without going out 
of Britain, we may find other impressive illustrations. For, as Dr. Skene 
says, "it is quite certain that we have many oaks which have passed 
their thousand years, and some which may be much older." Another 
way of looking at the insurgence of life is to think of some of the extraor- 
dinary haunts which many living creatures have sought out. Colonel 
Meinertzhagen, speaking recently of the lofty Tibetan plateau, directed 
attention to the herds of antelopes and kiangs (wild ponies) that seem to 


be able to thrive on next to nothing! The explorer marked out with his 
field-glass an area where he saw a small herd of kiangs feeding, and then 
visited the spot. Measuring a space one hundred yards by ten, he gathered 
up every scrap of vegetation, and the result was a quaint collection 
seventeen withered blades of coarse grass and seven small alpines not 
enough to feed a guinea-pig! Of course, the kiangs had been there before 
him, but there was little but very frugal fare all around. Meinertzhagen, 
to whom we owe much information on the altitude of bird flight, saw a 
flock of swifts at 18,800 feet. At 19,950 feet he shot a raven which showed 
undue inquisitiveness as to his movements; at 21,059 f eet > t ' ie highest 
point reached, he found a family of wall-creepers dainty little refugees 
of the mountains. Facts like these must be taken into consideration in 
our total conception of life, for they are surely as essential to the picture 
as the semi-permeability of the cell-membrane, or any other fundamental 
fact of life-structure. No doubt hunger is a sharp spur; the impelling 
power of the struggle for existence cannot be gainsaid; but we cannot get 
away from the impression that we must also allow for something 
analogous to the spirit of adventure. At all events, the facts show that 
while the environment selects organisms, often winnowing very roughly, 
there are other cases where organisms select their environment, and often 
adventurously. There is a quality of tentativeness in many organisms, 
that look out not merely for niches of opportunity into which to slink, 
but for new kingdoms to conquer. 

THE FACT OF BEAUTY. No one who studies Animate Nature can get 
past the fact of Beauty. It is as real in its own way as the force of 
gravity. It used to be spoken of as though it were a quality of the exotic 
of the Orchid and the Bird of Paradise now we feel it most at our 
doors. St. Peter's lesson has been learned, and we find naught common 
on the earth. As one of our own poets has said: Beauty crowds us all our 
life. We maintain that all living things are beautiful; save those which 
do not live a free life, those that are diseased or parasitised, those that 
are half-made, and those which bear the the marks of man's meddling 
fingers monstrosities, for instance, which are naturally non-viable, 
but live a charmed life under human protection. With these excep- 
tions all living creatures are beautiful, especially when we see them 
in their natural surroundings. To those who maintain that Animate 
Nature is spotted with ugliness, we would reply that they are allowing 
themselves to be preoccupied with the quite exceptional cases to which 
we have referred, or that they are unable to attain the detachment 
required in order to appreciate the esthetic points of, say, a snake or any 
other creature against which there is a strong racial or personal prejudice. 


To call a jellyfish anything but beautiful is either a confusion of thought 
or a submission to some unpleasant association, such as being severely 
stung when bathing. That there are many quaint, whimsical, grotesque 
creatures must be granted, to which conventionally minded zoologists 
who should have known better have given names like Moloch horridus, 
but we have never found any dubiety in the enthusiasm with which artists 
have greeted these delightfully grotesque animals; and the makers of 
beauty surely form the court of appeal for all such cases. 

When we say that all free-living, fully formed, healthy living creatures 
are beautiful, we mean that they excite in the spectator the characteristic 
kind of emotion which is called esthetic. The thing of beauty is a joy for 
ever. The esthetic emotion is distinctive; it brings no satiety; it is annexed 
to particular qualities of shape, colour, and movement; it grows as we 
share it with others; it grips us as organisms, body and soul, and remains 
with us incarnate. Why should the quality of exciting this distinctive emo- 
tion be pervasive throughout the world of organisms, as compelling in new 
creatures which the human eye never saw before as in the familiar 
favourites with which our race has grown up? It is possible that some 
light is thrown on this question when we analyse the esthetic delight which 
every normally constituted man feels when he watches the Shetland ponies 
racing in the field, the kingfisher darting up the stream like an arrow made 
of a piece of rainbow, the mayflies rising in a living cloud from a quiet 
stretch of the river, or the sea-anemones nestling like flowers in the niches 
of the seashore rocks. The forms, the colours, the movements, set up 
agreeable rhythmic processes in our eyes, agreeable rhythmic messages 
pass to our brain, and the good news the pleasedness is echoed through- 
out the body, in the pulse, for instance, and in the beating of the heart, as 
Wordsworth so well knew. The esthetic emotion is certainly associated 
with a pleasing bodily resonance; in other words, it has its physiological 
side. The second factor in our esthetic delight is perceptual. The "form" 
of what we contemplate is significant for us and satisfies our feeling. The 
more meaning is suffused into the material, the more our sense of beauty 
is enhanced. The lines and patterns and colours of living creatures go to 
make up a "form" which almost never disappoints. . . . We suggest for 
consideration the general conclusion that all free-living, full-grown, 
wholesome organisms have the emotion-exciting quality of beauty. And 
is not our humanly sympathetic appreciation of this protean beauty of 
the world inherent and persistent in us as also part of the same world of 
life, and evolved far enough to realise it more fully, communicate it tG 
each other more clearly? 




From Microbe Hunters 

man named Leeuwenhoek looked for the first time into a mysterious 
new world peopled with a thousand different kinds of tiny beings, some 
ferocious and deadly, others friendly and useful, many of them more im- 
portant to mankind than any continent or archipelago. 

Leeuwenhoek, unsung and scarce remembered, is now almost as un- 
known as his strange little animals and plants were at the time he dis- 
covered them. This is the story of Leeuwenhoek, the first of the microbe 
hunters. . . . Take yourself back to Leeuwenhoek's day, two hundred and 
fifty years ago, and imagine yourself just through high school, getting 
ready to choose a career, wanting to know 

You have lately recovered from an attack of mumps, you ask your father 
what is the cause of mumps, and he tells you a mumpish evil spirit has got 
into you. His theory may not impress you much, but you decide to make 
believe you believe him and not to wonder any more about what is mumps 
because if you publicly don't believe him you are in for a beating and 
may even be turned out of the house. Your father is Authority. 

That was the world about three hundred years ago, when Leeuwenhoek 
was born. It had hardly begun to shake itself free from superstitions, it was 
barely beginning to blush for its ignorance. It was a world where science 
(which only means trying to find truth by careful observation and clear 
thinking) was just learning to toddle on vague and wobbly legs. It was a 
world where Servetus was burned to death for daring to cut up and 
examine the body of a dead man, where Galileo was shut up for life for 
daring to prove that the earth moved around the sun. 



Antony Leeuwenhoek was born in 1632 amid the blue windmills and 
low streets and high canals of Delft, in Holland. His family were burghers 
of an intensely respectable kind and I say intensely respectable because 
they were basket-makers and brewers, and brewers are respectable and 
highly honored in Holland. Leeuwenhoek's father died early and his 
mother sent him to school to learn to be a government official, but he left 
school at sixteen to be an apprentice in a dry-goods store in Amsterdam. 
That was his university. . . . 

At the age of twenty-one he left the dry-goods store, went back to Delft, 
married, set up a dry-goods store of his own there. For twenty years after 
that very little is known about him, except that he had two wives (in suc- 
cession) and several children most of whom died, but there is no doubt 
that during this time he was appointed janitor of the city hall of Delft, and 
that he developed a most idiotic love for grinding lenses. He had heard 
that if you very carefully ground very little lenses out of clear glass, you 
would see things look much bigger than they appeared to the naked eye. . . . 

It would be great fun to look through a lens and see things bigger than 
your naked eye showed them to you! But buy lenses? Not Leeuwenhoek! 
There never was a more suspicious man. Buy lenses? He would make 
them himself! During these twenty years of his obscurity he went to spec- 
tacle-makers and got the rudiments of lens-grinding. He visited alchemists 
and apothecaries and put his nose into their secret ways of getting metals 
from ores, he began fumblingly to learn the craft of the gold- and silver- 
smiths. He was a most pernickety man and was not satisfied with grinding 
lenses as good as those of the best lens-grinder in Holland, they had to be 
better than the best, and then he still fussed over them for long hours. 
Next he mounted these lenses in little oblongs of copper or silver or gold, 
which he had extracted himself, over hot fires, among strange smells and 
fumes. . . . 

Of course his neighbors thought he was a bit cracked but Leeuwenhoek 
went on burning and blistering his hands. Working forgetful of his 
family and regardless of his friends, he bent solitary to subtle tasks in still 
nights. The good neighbors sniggered, while that man found a way to 
make a tiny lens, less than one-eighth of an inch across, so symmetrical, so 
perfect, that it showed little things to him with a fantastic clear enormous- 
ness. . . . 

Now this self-satisfied dry-goods dealer began to turn his lenses onto 
everything he could get hold of. He looked through them at the muscle 
fibers of a whale and the scales of his own skin. He went to the butcher 
shop and begged or bought ox-eyes and was amazed at how prettily the 
crystalline lens of the eye of the ox is put together. He peered for hours ar 


the build of the hairs of a sheep, of a beaver, of an elk, that were trans- 
formed from their fineness into great rough logs under his bit of glass. He 
delicately dissected the head of a fly; he stuck its brain on the fine needle 
of his microscope how he admired the clear details of the marvelous big 
brain of that fly! He examined the cross-sections of the wood of a dozen 
different trees and squinted at the seeds of plants. He grunted "Impos- 
sible!" when he first spied the outlandish large perfection of the sting of a 
flea and the legs of a louse. That man Leeuwenhoek was like a puppy who 
sniffs with a totally impolite disregard of discrimination at every object 
of the world around him! 


But at this time, in the middle of the seventeenth century, great things 
were astir in the world. Here and there in France and England and Italy 
rare men were thumbing their noses at almost everything that passed for 
knowledge. "We will no longer take Aristotle's say-so, nor the Pope's 
say-so," said these rebels. "We will trust only the perpetually repeated 
observations of our own eyes and the careful weighings of our scales; we 
will listen to the answers experiments give us and no .other answers!" So 
in England a few of these revolutionists started a society called The Invisi- 
ble College, it had to be invisible because that man Cromwell might have 
hung them for plotters and heretics if he had heard of the strange ques- 
tions they were trying to settle. 

. . . Remember that one of the members of this college was Robert Boyle, 
founder of the science of chemistry, and another was Isaac Newton. Such 
was the Invisible College, and presently, when Charles II came to the 
throne, it rose from its depths as a sort of blind-pig scientific society to the 
dignity of the name of the Royal Society of England. And they were 
Antony Leeuwenhoek's first audience! There was one man in Delft who 
did not laugh at Antony Leeuwenhoek, and that was Regnier de Graaf, 
whom the Lords and Gentlemen of the Royal Society had made a corre- 
sponding member because he had written them of interesting things he 
had found in the human ovary. Already Leeuwenhoek was rather surly and 
suspected everybody, but he let de Graaf peep through those magic eyes 
of his, those little lenses whose equal did not exist in Europe or England 
or the whole world for that matter. What de Graaf saw through those 
microscopes made him ashamed of his own fame and he hurried to write 
to the Royal Society: 

"Get Antony Leeuwenhoek to write you telling of his discoveries." 

And Leeuwenhoek answered the request of the Royal Society with all 
the confidence of an ignorant man who fails to realize the profouncj 


wisdom of the philosophers he addresses. It was a long letter, it rambled 
over every subject under the sun, it was written with a comical artlessness 
in the conversational Dutch that was the only language he knew. The title 
of that letter was: "A Specimen of some Observations made by a Micro- 
scope contrived by Mr. Leeuwenhoek, concerning Mould upon the Skin, 
Flesh, etc.; the Sting of a Bee, etc." The Royal Society was amazed, the 
sophisticated and learned gentlemen were amused but principally the 
Royal Society was astounded by the marvelous things Leeuwenhoek told 
them he could see through his new lenses. The Secretary of the Royal 
Society thanked Leeuwenhoek and told him he hoped his first communica- 
tion would be followed by others. It was, by hundreds of others over a 
period of fifty years. They were talkative letters full of salty remarks about 
his ignorant neighbors, of exposures of charlatans and of skilled explodings 
of superstitions, of chatter about his personal health but sandwiched be- 
tween paragraphs and pages of this homely stuff, in almost every letter, 
those Lords and Gentlemen of the Royal Society had the honor of reading 
immortal and gloriously accurate descriptions of the discoveries made by 
the magic eye of that janitor and shopkeeper. What discoveries! 

. . . When Leeuwenhoek was born there were no microscopes but only 
crude hand-lenses that would hardly make a ten-cent piece look as large as 
a quarter. Through these without his incessant grinding of his own mar- 
velous lenses that Dutchman might have looked till he grew old without 
discovering any creature smaller than a cheese-mite. You have read that 
he made better and better lenses with the fanatical persistence of a lunatic; 
that he examined everything, the most intimate things and the most 
shocking things, with the silly curiosity of a puppy. Yes, and all this 
squinting at bee-stings and mustache hairs and what-not were needful to 
prepare him for that sudden day when he looked through his toy of a gold- 
mounted lens at a fraction of a small drop of clear rain water to discover 

What he saw that day starts this history. Leeuwenhoek was a maniac ob- 
server, and who but such a strange man would have thought to turn his 
lens on clear, pure water, just come down from the sky? What could there 
be in water but just water? You can imagine his daughter Maria she 
was nineteen and she took such care of her slightly insane father! watch- 
ing him take a little tube of glass, heat it red-hot in a flame, draw it out to 
the thinnest of a hair. . . . 

He squints through his lens. He mutters guttural words under his 
breath. . . . 

Then suddenly the excited voice of Leeuwenhoek: "Come here! Hurry! 
There are little animals in this rain water. . . . They swim! They play 


around! They are a thousand times smaller than any creatures we can see 
with our eyes alone. . . . Look! See what I have discovered!" 

Leeuwenhoek's day of days had come. . . . This janitor of Delft had 
stolen upon and peeped into a fantastic sub-visible world of little things, 
creatures that had lived, had bred, had battled, had died, completely 
hidden from and unknown to all men from the beginning of time. Beasts 
these were of a kind that ravaged and annihilated whole races of men ten 
millions times larger than they were themselves. Beings these were, more 
terrible than fire-spitting dragons or hydra-headed monsters. They were 
silent assassins that murdered babes in warm cradles and kings in sheltered 
places. It was this invisible, insignificant, but implacable and sometimes 
friendly world that Leeuwenhoek had looked into for the first time of all 
men of all countries. 

This was Leeuwenhoek's day of days. . . . 


. . . How marvelous it would be to step into that simple Dutchman's 
shoes, to be inside his brain and body, to feel his excitement it is almost 
nausea! at his first peep at those cavorting "wretched beasties." 

That was what he called them, and this Leeuwenhoek was an unsure 
man. Those animals were too tremendously small to be true, they were 
too strange to be true. So he looked again, till his hands were cramped 
with holding his microscope and his eyes full of that smarting water that 
comes from too-long looking. But he was right! Here they were again, 
not one kind of little creature, but here was another, larger than the first, 
"moving about very nimbly because they were furnished with divers in- 
credibly thin feet." Wait! Here is a third kind and a fourth, so tiny I 
can't make out his shape. But he is alive! He goes about, dashing over 
great distances in this world of his water-drop in the little tube. . . . What 
nimble creatures! 

"They stop, they stand still as 'twere upon a point, and then turn them- 
selves round with that swiftness, as we see a top turn round, the circum- 
ference they make being no bigger than that of a fine grain of sand." So 
wrote Leeuwenhoek. . . . 

But where did these outlandish little inhabitants of the rainwater come 
from? Had they come down from the sky? Had they crawled invisibly 
over the side of the pot from the ground? Or had they been created out of 
nothing by a God full of whims? Well, there was only one way to find 
out where they came from. "I will experiment!" he muttered. 

. . . Then he took a big porcelain dish, "glazed blue within," he washed 
it clean, out into the rain he went with it and put it on top of a big box so 


that the falling raindrops would splash no mud into the dish. The first 
water he threw out to clean it still more thoroughly. Then intently he 
collected the next bit in one of his slender pipes, into his study he went 
with it. ... 

"I have proved it! This water has not a single little creature in it! They 
do not come down from the sky!" 

But he kept that water; hour after hour, day after day he squinted at it 
and on the fourth day he saw those wee beasts beginning to appear in 
the water along with bits of dust and little flecks of thread and lint. That 
was a man from Missouri! Imagine a world of men who would submit all 
of their cocksure judgments to the ordeal of the common-sense experiments 
of a Leeuwenhoek! 

Did he write to the Royal Society to tell them of this entirely unsus- 
pected world of life he had discovered? Not yet! He was a slow man. He 
turned his lens onto all kinds of water, water kept in the close air of his 
study, water in a pot kept on the high roof of his house, water from the 
not-too-clean canals of Delft and water from the deep cold well in his 
garden. Everywhere he found those beasts. He gaped at their enormous 
littleness, he found many thousands of them did not equal a grain of sand 
in bigness, he compared them to a cheese-mite and they were to this filthy 
little creature as a bee is to a horse. He was never tired with watching them 
"swim about among one another gently with a swarm of mosquitoes in the 
air. . . ." 

Of course this man was a groper. He was a groper and a stumbler as all 
men are gropers, devoid of prescience, and stumblers, finding what they 
never set out to find. His new beasties were marvelous but they were not 
enough for him, he was always poking into everything, trying to see more 
closely, trying to find reasons. Why is the sharp taste of pepper ? That was 
what he asked himself one day, and he guessed: "There must be little 
points on the particles of pepper and these points jab the tongue when you 
eat pepper " 

But are there such little points? 

He fussed with dry pepper. He sneezed. He sweat, but he couldn't get 
the grains of pepper small enough to put under his lens. So, to soften it, 
he put it to soak for several weeks in water. Then with fine needles he 
pried the almost invisible specks of the pepper apart, and sucked them up 
in a little drop of water into one of his hair-fine glass tubes. He looked 

Here was something to make even this determined man scatter-brained. 
He forgot about possible small sharp points on the pepper. With the in- 
terest of an intent little boy he watched the antics of "an incredible number 


of little animals, of various sorts, which move very prettily, which tumble 
about and sidewise, this way and that!" 

So it was Leeuwenhoek stumbled on a magnificent way to grow his new 
little animals. 

And now to write all this to the great men off there in London! Artlessly 
he described his own astonishment to them. Long page after page in a 
superbly neat handwriting with little common words he told them that 
you could put a million of these little animals into a coarse grain of sand 
and that one drop of his pepper-water, where they grew and multiplied so 
well, held more than two-million seven-hundred-thousand of them. . . . 

This letter was translated into English. It was read before the learned 
skeptics . . . and it bowled the learned body over! What! The Dutchman 
said he had discovered beasts so small that you could put as many of them 
into one little drop of water as there were people in his native country? 
Nonsense! The cheese mite was absolutely and without doubt the smallest 
creature God had created. 

But a few of the members did not scoff. This Leeuwenhoek was a con- 
foundedly accurate man : everything he had ever written to them they had 
found to be true. ... So a letter went back to the scientific janitor, begging 
him to write them in detail the way he had made his microscope, and his 
method of observing. 

. . . He replied to them in a long letter assuring them he never told any- 
thing too big. He explained his calculations (and modern microbe hunters 
with all of their apparatus make only slightly more accurate ones!); he 
wrote these calculations out, divisions, multiplications, additions, until his 
letter looked like a child's exercise in arithmetic. He finished by saying 
that many people of Delft had seen with applause! these strange new 
animals under his lens. He would send them affidavits from prominent 
citizens of Delft two men of God, one notary public, and eight other 
persons worthy to be believed. But he wouldn't tell them how he made 
his microscopes. 

That was a suspicious man! He held his little machines up for people to 
look through, but let them so much as touch the microscope to help them- 
selves to see better and he might order them out of his house. . . . He was 
like a child anxious and proud to show a large red apple to his playmates 
but loath to let them touch it for fear they might take a bite out of it. 

So the Royal Society commissioned Robert Hooke and Nehemiah Grew 
to build the very best microscopes, and brew pepper water from the finest 
quality of black pepper. And, on the i5th of November, 1677, Hooke came 
carrying his microscope to the meeting agog for Antony Leeuwenhoek 
had not lied. Here they were, those enchanted beasts I The members rose 


from their seats and crowded round the microscope. They peered, they 
exclaimed: this man must be a wizard observer! That was a proud day 
for Leeuwenhoek. And a little later the Royal Society made him a Fellow, 
sending him a gorgeous diploma of membership in a silver case with the 
coat of arms of the society on the cover. "I will serve you faithfully during 
the rest of my life," he wrote them. And he was as good as his word, for 
he mailed them those conversational mixtures of gossip and science till 
he died at the age of ninety. But send them a microscope? Very sorry, but 
that was impossible to do, while he lived. 


Those little animals were everywhere! He told the Royal Society of 
finding swarms of those sub-visible beings in his mouth of all places: 
"Although I am now fifty years old," he wrote, "I have uncommonly well- 
preserved teeth, because it is my custom every morning to rub my teeth 
very hard with salt, and after cleaning my large teeth with a quill, to rub 
them vigorously with a cloth. . . ." But there still were little bits of white 
stuff between his teeth, when he looked at them with a magnifying 
mirror. . . . 

What was this white stuff made of? 

From his teeth he scraped a bit of this stuff, mixed it with pure rain 
water, stuck it in a little tube on to the needle of his microscope, closed the 
door of his study 

What was this that rose from the gray dimness of his lens into clear 
distinctness as he brought the tube into the focus? Here was an unbe- 
lievably tiny creature, leaping about in the water of the tube "like the fish 
called a pike." There was a second kind that swam forward a little way, 
then whirled about suddenly, then tumbled over itself in pretty somer- 
saults. There were some beings that moved sluggishly and looked like wee 
bent sticks, nothing more, but that Dutchman squinted at them till his 
eyes were red-rimmed and they moved, they were alive, no doubt of it! 
There was a menagerie in his mouth! There were creatures shaped like 
flexible rods that went to and fro with the stately carriage of bishops in 
procession, there were spirals that whirled through the water like violently 
animated corkscrews. . . . 

You may wonder that Leeuwenhoek nowhere in any of those hundreds 
of letters makes any mention of the harm these mysterious new little 
animals might do to men. He had come upon them in drinking water, 
spied upon them in the mouth; as the years went by he discovered them in 
the intestines of frogs and horses, and even in his own discharges; in 
swarms he found them on those rare occasions when, as he says, "he was 


troubled witH a looseness." But not for a moment did he guess that his 
trouble was caused by those little beasts, and from his unimaginativeness 
and his carefulness not to jump to conclusions modern microbe hunters 
if they only had time to study his writings could learn a great deal. . . . 

The years went by. He tended his little dry-goods store, he saw to it the 
city hall of Delft was properly swept out, he grew more and more crusty 
and suspicious, he looked longer and longer hours through his hundreds 
of microscopes, he made a hundred amazing discoveries. In the tail of a 
little fish stuck head first into a glass tube he saw for the first time of all 
men the capillary blood vessels through which blood goes from the arteries 
to the veins so he completed the Englishman Harvey's discovery of the 
circulation of the blood. The most sacred and improper and romantic 
things in life were only material for the probing, tireless eyes of his lenses. 
Leeuwenhoek discovered the human sperm, and the cold-blooded science of 
his searching would have been shocking, if he had not been such a com- 
pletely innocent man! The years went by and all Europe knew about him. 
Peter the Great of Russia came to pay his respects to him, and the Queen 
of England journeyed to Delft only to look at the wonders to be seen 
through the lenses of his microscopes. He exploded countless superstitions 
for the Royal Society, and aside from Isaac Newton and Robert Boyle he 
was the most famous of their members. But did these honors turn his 
head? They couldn't turn his head because he had from the first a suffi- 
ciently high opinion of himself! His arrogance was limitless but it was 
equaled by his humility when he thought of that misty unknown that he 
knew surrounded himself and all men. . . . 

He was an amazingly healthy man, and at the age of eighty his hand 
hardly trembled as he held up his microscope for visitors to peep at his 
little animals or to exclaim at the unborn oysters. . . . Years after his dis- 
covery of the microbes in his mouth one morning in the midst of his coffee 
drinkings he looked once more at the stuff between his teeth 

What was this? There was not a single little animal to be found. Or 
there were no living animals rather, for he thought he could make out the 
bodies of myriads of dead ones and maybe one or two that moved feebly, 
as if they were sick. "Blessed Saints!" he growled: "I hope some great Lord 
of the Royal Society doesn't try to find those creatures in his mouth, and 
fail, and then deny my observations. . . ." 

But look here! He had been drinking coffee, so hot it had blistered his 
lips, almost. He had looked for the little animals in the white stuff from 
between his front teeth. It was j ust after the coffee he had looked there- 

With the help of a magnifying mirror he went at his back teeth. Presto! 


"With great surprise I saw an incredibly large number of little animals, 
and in such an unbelievable quantity of the aforementioned stuff, that it 
is not to be conceived of by those who have not seen it with their own 
eyes." Then he made delicate experiments in tubes, heating the water with 
its tiny population to a temperature a little warmer than that of a hot bath. 
In a moment the creatures stopped their agile runnings to and fro. He 
cooled the water. They did not come back to life so! It was that hot coffee 
that had killed the beasties in his front teeth! . . . 

If Antony Leeuwenhoek failed to see the germs that cause human dis- 
ease, if he had too little imagination to predict the role of assassin for his 
wretched creatures, he did show that sub-visible beasts could devour and 
kill living beings much larger than they were themselves. He was fussing 
with mussels, shellfish that he dredged up out of the canals of Delft. He 
found thousands of them unborn inside their mothers. He tried to make 
these young ones develop outside their mothers in a glass of canal water. 
"I wonder," he muttered, "why our canals are not choked with mussels, 
when the mothers have each one so many young ones inside them!" Day 
after day he poked about in his glass of water with its slimy mass of 
embryos, he turned his lens on to them to see if they were growing but 
what was this? Astounded he watched the fishy stuff disappear from 
between their shells it was being gobbled up by thousands of tiny 
microbes that were attacking the mussels greedily. . . . 

"Life lives on life it is cruel, but it is God's will," he pondered. "And 
it is for our good, of course, because if there weren't little animals to eat up 
the young mussels, our canals would be choked by those shellfish, for 
each mother has more than a thousand young ones at a time!" So Antony 
Leeuwenhoek accepted everything and praised everything, and in this he 
was a child of his time, for in his century searchers had not yet, like Pasteur 
who came after them, begun to challenge God, to shake their fists at the 
meaningless cruelties of nature toward mankind, her children. . . . 

He passed eighty, and his teeth came loose as they had to even in his 
strong body; he didn't complain at the inexorable arrival of the winter of 
his life, but he jerked out that old tooth and turned his lens onto the little 
creatures he found within that hollow root why shouldn't he study 
them once more? There might be some little detail he had missed those 
hundred other times! Friends came to him at eighty-five and told him to 
take it easy and leave his studies. He wrinkled his brow and opened wide 
his still bright eyes: "The fruits that ripen in autumn last the longest!" he 
told them he called eighty-five the autumn of his life! . . . 

That was the first of the microbe hunters. In 1723, when he was ninety- 
one years old and on his deathbed, he sent for his friend Hoogvliet. He 


could not lift his hand. His once glowing eyes were rheumy and their lids 
were beginning to stick fast with the cement of death. He mumbled: 

"Hoogvliet, my friend, be so good as to have those two letters on the 
table translated into Latin. . . . Send them to London to the Royal 
Society " 

So he kept his promise made fifty years before, and Hoogvliet wrote, 
along with those last letters: "I send you, learned sirs, this last gift of my 
dying friend, hoping that his final word will be agreeable to you." 


Where Life Begins 


From The Advancing Front of Science 

power microscope. . . . Within the delicate membrane of the cell 
wall, the protoplasm churns and flows. Perpetually the living stuff is 
on the move, and yet it maintains from moment to moment a certain dif- 
ferentiation in which we may identify relatively stable parts of the cell. 
Central, or nearly central, in this dynamic structure is a region, generally 
spherical or oval in shape, that appears more dense than its surrounding 
medium. This interior protoplasm is the "cell nucleus," and the sur- 
rounding thinner fluid is the "cytoplasm." All types of cells but a very 
few, like bacteria and some algae and blood corpuscles, have an easily 
recognizable nucleus. 

It is possible to puncture the cell wall without killing the cell. It is pos- 
sible to remove much of the cytoplasm without killing the cell. Indeed, 
the loss will be made good by the manufacture of new cytoplasm. The 


cell, like the tadpole, is capable of a limited regeneration. But if you in- 
jure the nucleus, the case is quite different. That inner zone is vulnerable. 
It cannot long survive the removal of any part of its substance. 

The crucial role of the nucleus may be demonstrated in another way if 
we select for experiment those peculiarly endowed units of protoplasm 
known as germ cells. These, the egg cell of the female and the sperm cell of 
the male, have through the evolutionary ages become specialized as carriers 
of life. Some years ago it was discovered that by treating the egg (that of 
a sea urchin, for example) with a salt solution, or by pricking it with a 
needle, or by other mechanical means, the cell could be artificially stimu- 
lated to develop and produce a new sea urchin. You might cut the egg in 
two, leaving the nucleus in one half. The half containing the nucleus 
could be fertilized, but the other half was sterile. In the case of some 
animals, in which the nucleus is a very small part of the egg, the removal 
of the nucleus left the egg nearly entire; but an egg so mutilated had no 
power of reproduction. 

Normally, in nature, fertilization is accomplished through penetration 
of the egg by the sperm, which makes contact with the nucleus and merges 
with it. The sperm cell is extremely small. It may bulk only a few hun- 
dredths the size of the egg. It consists of a bulbous nuclear head and a 
short thin trailing thread of cytoplasm. But small as it is, the sperm cell 
carries all the pattern of characteristics of the father which are to be 
inherited by the child. Might it not also carry the spark of life to one of 
those bereft eggs of our experiment the ovum from which the nucleus has 
been removed? This was tried, and it worked. When an egg fragment 
consisting only of cytoplasm was exposed to a sperm cell of its species, the 
sperm entered the fragment and by this merger supplied the necessary 
nuclear material for thereafter the fragment quickened, began to 
divide, and grew into a new individual. 

It is the nucleus, then, that is the captain of life. How potent it is, how 
packed its small volume, is graphically suggested by H. J. Muller in his 
book Out of the Night. Dr. Muller computes that if all the human sperm 
cells which are to be responsible for the next generation of the human 
species, some 2000 million individuals, could be gathered together in one 
place, they would occupy space equivalent to that of half an aspirin tablet. 
The corresponding number of egg cells, because of their larger component 
of cytoplasm, would fill a 2-gallon pitcher. But since it is the nucleus that 
carries the stuff of life, we may consider only the nuclei of these eggs and 
reckon that they would occupy no more space than the sperm cells. Thus, 
the essential substance of both eggs and sperm could be contained in a 
capsule the size of an aspirin tablet. 


It is indeed difficult to believe, as Dr. Muller points out, "that in this 
amount of physical space there now actually lie all the inheritable struc- 
tures for determining and for causing the production of all the multi- 
tudinous characteristics of each individual person of the whole future world 
population. Only, of course, this mass of leaven today is scattered over the 
face of the Earth in several billion separate bits. Surely, then, this cell sub- 
stance is incomparably more intricate, as well as more portentous, than 
anything else on Earth." 

Some of its intricacy can be made visible under a microscope, by using 
suitable stains. Then we see the organs of the nucleus, the minute sausage- 
shaped "chromosomes." 1 It is not only in the germ cells, but also in the 
somatic or body cells, that the chromosomes are found, the structural pat- 
tern being repeated in every cell. And the pattern is specific. Every species 
of plant and animal has its typical number of these nuclear organs, and 
for each there is a standard shape, size, and arrangement. . . . 

One of the most productive researches of the twentieth century is the 
tracking down of the relationship which these microscopic nuclear bodies 
bear to the factor of heredity. The studies were focused on fruit flies. 
Thomas Hunt Morgan and his associates, working at Columbia Univer- 
sity, cultured the tiny insects (Drosophila melanogaster) in bottles, pro- 
vided the optimum of conditions for their growth and reproduction, and 
kept exact pedigrees through many generations. As new flies hatched out, 
the biologists examined the young individuals for possible changes in 
physical character. It was not long before they were finding changes. 

For example: the bulging eyes of drosophila are normally red, but occa- 
sionally a white-eyed child would hatch out. Morgan and his men were 
able to correlate this mutation with a change in a certain region of one of 
the chromosomes of the egg which gave birth to the fly. Later they found 
nine variations in the wings, and following that came discovery of scores 
of variations affecting practically every visible characteristic of the fly 
physical changes which the investigators were able to relate to changes in 
the chromosomes. . . . 

By these and other experiments a new credence was given to an idea 
that had long been held as an inference. They indicate that the chromo- 
somes are not simple continuous wholes, but are complex patterns made 
of smaller interchangeable units. And these units are the "genes." 

No one has ever seen a gene. It is too fine for even the ultramicroscope 
to enlarge to visibility. But just as we postulate invisible atoms to account 
for the chemical and optical behavior of matter, so we find it necessary to 

1 For a discussion of the work of the chromosomes and genes, see "You and Heredity," 
by Amram Scheinfeld, page 521. 


postulate invisible genes to account for the developmental behavior o 
protoplasm. Genes are the unit structures, the atoms of heredity. 

Nor is that all. Recent findings bring evidence of a still more funda- 
mental role. Experiments show that the injury of genes may be a very 
serious event in the history of a cell. The loss of certain genes means death. 
And this suggests that the gene's function in the cell activities is not merely 
to control heredity, but also to control life. 

Discovery of the primary vital role of the genetic unit is the work of 
M. Demerec, a geneticist of the Carnegie Institution of Washington, 
member of its Department of Genetics at Cold Spring Harbor, Long 
Island. For some years Dr. Demerec has been watching the effect of muta- 
tions on the reproductive capacity of drosophila. He was impressed by 
some experiments completed five years ago by J. T. Patterson at the Uni- 
versity of Texas. Dr. Patterson found that out of fifty-nine mutations in 
three well-defined chromosomal regions, fifty-one were what he called 
"lethals." That is to say, when a fertilized egg carried these changed 
chromosomes (in which certain genes were missing), the egg developed 
only part way and died as an embryo. The gene deficiencies were fatal to 
development, therefore lethal to the fly. 

Demerec followed this pioneer work with an intensive search into the 
somatic or body cells of the flies. He found that not only were the germ 
cells rendered incapable of development, as Patterson's results showed, 
but the growing body cells, which by a special treatment had been made 
deficient in these same ways, were rendered powerless to grow. And the 
cells died though adjacent body cells, which carried no deficiencies, 
showed no such effects. Demerec's later work has demonstrated that 
more than half of Patterson's lethals are cell lethals. And by further exten- 
sion of experiment and inference the Carnegie biologist arrives at the 
conclusion that some of these cell lethals are chargeable to the loss of a 
very few genes, possibly only one gene. 

How large is this genetic unit? No one knows, and apparently the only 
present way of approaching the problem is to find out how many genes 
there are in the chromosomes, divide the total length of chromosomal 
material by the number of genes, and so arrive at an average value. 

The number of genes may be assumed to correspond to the number of 
places in the chromosomes at which changes occur. By mathematical anal- 
ysis of mutations it has been figured that in drosophila there are about 
3000 such places, which means that each cell has at least 3000 genes. 

Quite recently a new and more direct method of determining the 


number of genes has been introduced through the work of Theophilus S. 
Painter, at the University of Texas. The larva of the fruit fly, like man 
and other animals, has salivary glands situated near its mouth, and in flies 
these glands are made of giant cells. The cells are many times larger than 
the other body cells, and the chromosomes are about 150 times the size of 
the chromosomes of the germ cells. This fact has been known for several 
decades, but apparently no geneticist thought to search the chromosomes 
of these giant cells for fine-structure details of mutations until Dr. Painter 
took up the work in 1932. He found that under a certain technique of 
staining and illumination, the giant chromosomes revealed themselves as 
chainlike structures of varying width made up of transverse bands of 
different sizes, each band showing a highly individual pattern of yet finer 
parts. The band is not the gene no geneticist claims that but it appears 
to be individual to the gene, each is the holder of a gene, "the house in 
which the gene lives," to quote Painter's picturesque phrase. Therefore, 
by counting the number of bands, we should arrive at the number of 

Here we are attempting to separate structures so fine that they approach 
the limit of visibility under the most powerful magnification. Early counts 
showed about 2700 bands distinguishable, but recently Calvin B. Bridges, 
using a more delicate technique, counted 5000 bands. There may be more, 
and with further advances in microscopy we may some day be able to see 
them one by one. Painter has suggested a total of 10,000 as a guess. And 
some late speculations of Muller open up the possibility of an even larger 

But, in order to be very conservative, suppose we take Bridges' count as 
our basis. If there are approximately 5000 genes to the drosophila cell, then 
we may say that one gene is not more than the five-thousandth part of the 
chromosomal material. But the chromosomes, in turn, are probably not 
more than a hundred-thousandth part of the average cell. The gene then 
figures roughly as not more than one five-hundred-millionth of the total 
cell material. We arrive at a picture of a mechanism so delicately balanced, 
and of a unit so indispensable to the smooth running of this mechanism, 
that although the unit represents only the five-hundred-millionth part of 
the whole, its elimination is fatal. 

What is the nature of this indispensable unit of life? . . . 

The view generally held among geneticists favors the particle idea. Dr. 
Demerec pictures the gene as an organic particle, and suggests that it may 
be a single large molecule. The observed instability of certain genes seems 
evidence for this conception. Thus, it has been noticed that the genie pat- 
tern responsible for wing formation, which normally endows a fly with 


long wings, will sometimes change to a form producing short miniature 
wings, and later shift back to the long-wing structure. These alterations 
may be accounted for if we assume the gene to be a large molecule which 
suddenly loses one of its subgroups of atoms, and later recaptures and 
recombines the separated parts. Other evidence adduced from the study 
of unstable genes indicates that when a cell divides to form two cells, the 
genes do not divide, but each is exactly duplicated by the formation of a 
new gene next to the old one. This method of reproduction favors the 
supposition that the gene is a single molecule. 

If it is a single molecule, it must be a large one. Organic molecules of 
extremely complex structure are known to chemists. Some proteins consist 
of thousands of atoms. 

. . . The elimination of a single atom may so change the gene structure 
that its duplication is rendered impossible. And when gene duplication 
stops, cell division in many instances is blocked. 

Thus we are led to a view of the protoplasmic world in which a single 
small unit becomes critically important. Deprived of this small unit the 
gene cannot function; deprived of the gene the chromosomes cannot func- 
tion; and with the paralysis of the chromosomes the functioning of the 
cell is halted. Cell growth stops, reproduction ceases, life comes to an end. 
If life comes to an end with the failure of a gene, may we not infer that 
life begins with the functioning of the gene? 

Of that functioning we know only three results surely: (i) that in the 
process the gene is exactly duplicated, (2) that the gene occasionally 
mutates, (3) that genes somehow control and pass on to the developing 
organism the physical characteristics which distinguish it. But all these 
operations are manifest only in groups of genes. Indeed, we know genes 
only as they function in the closely related teamwork of the chromosomes. 
But suppose a gene should get separated from its fellows. Imagine one of 
these living molecules adrift in the cell fluid, or a wanderer in the body 
plasma. Could it function independently? If so, with what effect? 

Several years ago B. M. Duggar, of the University of Wisconsin, specu- 
lated on this possibility. Dr. Duggar suggested that a lone gene might be 
a destructive agent. He pointed to the filtrable virus. Might not the virus 
be simply a gene on the loose? 


The virus has been known for more than 40 years. It has long been a 
candidate for recognition as the most elementary living thing, and 
Duggar's suggestion offers presumptive argument for such rating. But first 
let us review what is known of the virus. Recent research can help us, for 


within the last 2 years an exciting discovery has been made. Wendell M. 
Stanley is the discoverer. 

Dr. Stanley is an organic chemist. A graduate of Earlham College, he 
spent postgraduate years at the University of Illinois working on leprosidal 
compounds, then studied in Germany on a fellowship from the National 
Research Council, and in 1931 joined the staff of the Rockefeller Institute 
for Medical Research in New York. In 1932 the Institute opened additional 
laboratories near Princeton, and Stanley went there with definite designs 
on the virus. 

The nature of the virus is one of the key problems of pathology. Such 
destructive diseases as infantile paralysis, influenza, parrot fever, rabies, 
"St. Louis" encephalitis or sleeping sickness, yellow fever, and certain types 
of tumorous growths are propagated by these invisible carriers; therefore 
virus investigation is a major project for medical research. Pathologists and 
other biologists have specialized on biological aspects, and have turned up 
many important facts about the physiological effects of the virus and its 
response to various agents. Stanley the chemist was asked to specialize on 
chemical aspects to find out, if he could, what a virus is in terms of mole- 
cules, and what the molecules are in terms of atoms: how large, how 
massive, how composed, how reactive ? 

He chose for his inquiry the oldest known virus, that which causes the 
tobacco mosaic disease. This is a pestilence dreaded by tobacco growers, 
for if one plant in a field contracts the disease, the infection usually spreads 
through the entire acreage, stunting the plants, puckering their foliage, 
and causing the leaves to assume the mottled appearance of a mosaic. Back 
in 1857, when mosaic disease was first recognized, it was confused with a 
plant pock affliction, and not until 1892 did the botanists realize that the 
two diseases are different. This discovery was made by the Russian inves- 
tigator Iwanowski, and he startled the bacteriologists of his day by 
announcing that the juice of infected tobacco-mosaic plants remained 
infectious after it had passed through a Chamberland filter. 

Now a Chamberland filter is a porcelain affair with pores so fine that if 
a pint of distilled water is placed in the filter, many days will elapse before 
the liquid percolates through, unless strong suction is applied. There was 
no known bacterium that could get through such minute holes. And yet, 
the agent which communicated the tobacco mosaic disease readily passed. 
Other experimenters confirmed Iwanowski's findings, and six years later 
the first filtrable carriers of an animal contagion were discovered in the 
foot-and-mouth disease. Since then scores of afflictions affecting plants, 
animals, and man have been identified as virus infections. . . . 

On the acres near Princeton, Stanley grew thousands of tobacco plants. 


infected them with the disease, later ground up the dwarfed, puckering, 
mottle-leafed plants, pressed them to a pulp, and collected the juices. 
Somewhere in the gallons was the virus. You could not see it, you could 
not accumulate it in a filter, you could not culture it in agar or in any of 
the soups used to grow bacteria. You knew it was there only by its destruc- 
tive effect. For if you took a drop of the juice and touched it to a healthy 
plant, within a few days the leaves showed the unmistakable signs of 
mosaic. The virus was there. But how to get at it chemically? 

The known ingredients of protoplasm may be grouped in five classes of 
substance: metal salts, carbohydrates, lipoids or fatty compounds, and 
proteins these last the most complex of all. There are certain enzymes 
which break up proteins. Protein splitters, or protein digesters, they are 
called. Pepsin, for example, does precisely that in the stomach, and will do 
the same in a test tube. What would it do to the virus? 

Stanley put some of the infectious tobacco juice in a test tube, poured 
in pepsin, kept the mixture at the temperature and in the other conditions 
favorable for pepsin digestion, and at the end of the experiment tested the 
solution for infection. It had none. Rubbed on the leaves of healthy tobacco 
plants it showed no power to transmit the disease. Obviously the pepsin 
had destroyed the infectious principle in the juice. But pepsin digests only 
proteins it has no effect on lipoids, hydrocarbons, carbohydrates, and 
salts. From this it seemed reasonable to conclude that the virus material is 

There are chemicals which precipitate proteins. These were tried on the 
virulent tobacco juice. Immediately certain substances dropped down as 
solid precipitates, and it was found that thereafter the juice had no power 
to infect. But when some of the precipitate was added to neutral liquid, 
the solution immediately became infectious. This plainly said that the 
disease carrier resided in the protein precipitate, and Stanley now began a 
campaign to trace the carrier down to its source. 

He dissolved the precipitate in a neutral liquid, and added an ammonium 
compound which has the faculty of edging protein out of solution without 
changing the protein. A cluster of crystals began to form at the bottom of 
the test tube somewhat as sugar crystals form in syrup. But these might 
not be a single pure stuff, so Stanley sought to refine them. He removed 
the crystals, dissolved them in a much larger volume of neutral liquid, 
and with the help again of the ammonium compound brought this more 
dilute solution to crystallization. His next step repeated the process, but 
with still greater proportion of the liquid. In this way, by increasing tfie 
dilution each time, the chemist carried his material through ten successive 
fractionations and recrystallizations. One would assume that by now the: 


substance was pure, that all extraneous materials had been separated out, 
also that all living matter had been eliminated for we know no plant or 
animal, no bacterium, no protoplasm, that can undergo crystallization and 
remain the same. So the experiment seemed ripe for a supreme test. 

Stanley took a pinch of the product of that tenth recrystallization, dis- 
solved it in a neutral fluid more than 100 million times its bulk, rubbed a 
drop of the solution on the leaves of a healthy tobacco plant, and awaited 
the result. The test was conclusive. Within the usual time the plant showed 
all signs of an acute outbreak of the mosaic disease. Surely in the crystals 
we have the virus. And since, by all rules of chemistry, the crystals have 
been refined to the pure state and may be accepted as an uncontaminated 
single substance, it seems reasonable to believe that the crystals arc the 

I have watched them through the microscope: a mass of white needle- 
like structures bristling in every direction. It is not supposed that each 
needle is a virus. Just as each crystal of sugar is made of numerous mole- 
cules of sugar, so it is presumed that each of these crystalline spikes is a 
cluster of millions of molecules of the protein, and that each molecule is a 
single virus. 

Stanley's chemical analysis shows that the virus molecule is composed of 
carbon, hydrogen, nitrogen, and oxygen. Unlike many other physiologically 
active proteins, it contains no sulphur and no phosphorus. Just how many 
atoms of each element are present, and the arrangement of the atoms in 
molecular architecture, are details still in process of investigation. But the 
evidence indicates that the molecules are enormous. 

Ingenious physical measurements of the molecules were recently made 
by The Svedberg, at the University of Upsala, and by Ralph W. G. 
Wyckoff, at the Rockefeller Institute, using centrifuges of the ultra type. 
The apparatus is a whirling machine capable of doing better than 100,000 
revolutions per minute. Dr. Svedberg's apparatus is made of steel, and is 
-driven by a stream of oil pumped at high pressure. Dr. Wyckoffs apparatus 
is made of an aluminum alloy, and its turbine is driven by compressed air. 
In both machines, the rotating part is housed in a chamber made of 3-inch 
armor-plate steel a safeguard to protect the operator in case of explosion. 
If a dime is placed in the ultracentrif uge, and the apparatus is rotated at a 
certain velocity, the centrifugal force is so great that the dime presses out 
with an effect equal to the weight of half a ton. The purpose, however, is 
not to perform trick stunts with dimes, but to separate mixtures of mole- 
cules, using a principle long familiar in the dairyman's cream separator. In 
the ultracentrif uge this principle is harnessed to the utmost degree of con- 
trol. Under the accelerated fling of centrifugal force generated by the 


rotating mechanism, molecules in solution are separated, each is thrown 
out with a speed proportional to its mass, and by timing the period 
required for its separation the molecular weight and size of any constituent 
may be determined. Dr. Stanley sent Professor Svedberg samples of his 
crystals, and at the same time supplied specimens to his colleague Dr. 
Wyckoflf, and to the test of this indirect weighing and measuring machine 
the substance was subjected. 

The results are in remarkable agreement. Both Svedberg and Wyckoff 
independently reported that the weight of Stanley's crystalline protein is 
approximately 17,000,000 (in terms of hydrogen's atomic weight of i). 
The largest molecule known up to this time was that of the animal protein 
called hemocyanin (which is the pigment of earthworm blood), with a 
molecular weight of about 5,000,000. Thus Stanley's find is more than 
three times heavier. In size it appears to be egg-shaped with a diameter of 
about 35 millimicrons. The corresponding dimension of the hemocyanin 
is 24 millimicrons. And a millimicron is 1/25,400,000 inch. 

The tobacco mosaic protein thus provides the chemists, the molecular 
architects, the microcosmic adventurers, with a perfectly enormous mole- 
cule for their exploration: a structure many times more massive and com- 
plex than anything heretofore analyzed. It must consist of hundreds of 
thousands of atoms, possibly of millions. 

It provides the biologists with an indubitable specimen of the invisible 
stuff that is responsible for so many human ills, and if we can learn in 
intimate detail the ways of the tobacco mosaic virus we may get some 
important flashes of information on the ways of the virus of the common 
cold and other hidden enemies of mankind. Many points of correspondence 
have recently been found, properties in which the plant virus shows char- 
acteristics similar to the animal virus. Thus, it is known that the common 
cold affects many species of animals. Similarly, the tobacco mosaic virus 
affects tomato, phlox, and spinach plants, as well as tobacco. . . . 

Another point of similarity between the tobacco mosaic virus and the 
virus of animal diseases lies in this: that both may be inactivated and 
rendered harmless. Thus Pasteur found that by drying the spinal cords of 
dogs which had died of hydrophobia, he obtained a material which was 
harmless; and yet it seemed to contain the principle of the hydrophobia 
carrier, for a person inoculated with the material gained a certain immu- 
nity to the disease. Stanley has found that by treating his crystalline protein 
with hydrogen peroxide, or formaldehyde, or other chemicals, or by expos- 
ing it to ultra-violet light, he causes its virulence to vanish. When the virus 
is rubbed on the leaves of healthy plants, no ill effects follow. And yet the 
crystals appear to be the same as those of the virulent untreated protein.. 


When they are analyzed by X-ray bombardment they show the same 
diffraction pattern, when weighed they show the same molecular weight, 
and, most important of all, when injected into animals they produce an 
antiserum which when mixed with solutions of active virulent virus is able 
to neutralize or render inactive such solutions. There are slight chemical 
differences, however, and it is Dr. Stanley's idea that the effect of the 
treatment is to alter certain active groups of the huge molecule to switch 
certain towers or ells of its architecture, as it were but to leave the struc- 
ture as a whole unchanged. These experiments with inactivation of the 
tobacco mosaic protein seem to promise results that will be helpful to the 
human pathologist searching the frontiers of immunization. . . . 

But man, whose virus diseases are of animal nature, wants to know of 
the virus that affects animals. Has any research progress been made in that 
direction? Yes, an interesting beginning, just announced. There is a highly 
contagious animal disease known as "infectious papillomatosis" which 
affects rabbits. It causes warty masses to grow on the ears and other parts 
of its victims, and has been attributed to a filtrable virus carrier. This 
disease was first described by R. E. Shope; and recently Wyckoff and 
J. W. Beard obtained some of the warty tissue from Dr. Shope, ground it 
up, made a solution of it, and subjected this solution to the new technique 
of the ultracentrifuge. In this way they isolated a heavy protein which 
when tested on healthy rabbits immediately communicated the disease. 
But rabbits frequently develop warts which are not infectious, and so as a 
further test the investigators obtained some of this noninfectious warty 
tissue, and subjected it to the same treatment. They were unable to obtain 
from this solution any heavy protein, though repeated trials were made. 
Apparently the giant molecules flung out of the solution of the infectious 
tissue are a \ irus which is not presen in other warts. And by weight and 
measurement the wart virus proves to be a tremendous molecular structure 
weighing something more than 20,000,000 and measuring about 40 milli- 
microns in diameter. Thus the first animal virus to be isolated is a larger, 
more massive, and presumably a more complex molecule than that of the 
first discovered plant virus, the carrier of tobacco mosaic. But all our 
evidence points to many similarities among these various disease-carrying 
substances, and very many lines of research are now being pushed with 
the tobacco mosaic protein on the idea that it is not only a virus but a 
representative species of the whole virus family, both plant and animal. 

Ic it alive? Stanley reminds you that it can be crystallized, a property 
that we think of as purely inanimate and wholly chemical. He points to 
the additional fact that it has not been cultured in a test tube. This would 
seem to say that it is not a bacterium. A few bacteria placed in a nutrient 


soup will rapidly multiply into uncounted millions, but the crystalline 
protein shows no growth behavior in a glass vessel, no metabolism, no 

And yet, observe what happens when it comes in contact with the inner 
tissue of a tobacco plant or other vegetable host. Instantly the molecules 
being to multiply. An almost imperceptible particle of a crystal will infect 
a plant, and in a few days the disease will spread through a field, producing 
an amount of virus millions of times that of the original. It exhibits a 
fecund ability to propagate itself, to extend its occupancy of space and 
time at the expense of its environment. Is not this a characteristic of living 

Perhaps the virus is a molecule of double personality, alive and yet not 
alive animated by its environment when that environment is specific to 
its nature, but passive in any other environment. The discovery of this 
substance and the elucidation of its properties is one of the most important 
biological advances of our century. 

The tobacco mosaic protein has certain apparent points of corrrespond- 
ence with the gene. The two appear to be of approximately the same order 
of size. Both are molecules that in certain surroundings undergo duplica- 
tion. Both suspend this reproductive faculty over long periods of time 
without losing the capacity to call it into action when conditions are 
favorable. The quiescence of genes in an unfertilized egg or in the cells 
of a resting seed, and the inactivity of the virus when stored in a bottle, 
are examples of the last-mentioned characteristic. 

There is still another parallel. The gene, as we know, is sometimes 
unstable. Stanley has found a somev* hat similar behavior in his crystalline 
protein. The common form of its disease is known as "tobacco" mosaic, 
and produces a green mottling of leaves. Recently there was discovered 
another strain of the disease which has been named "masked/* and a still 
more virulent form known as "acuba" which shows a yellow mottling. 
The crystals of acuba strain are larger, its solution is more silky and 
opalescent, its solubility is lower, and the ultracentrifuge shows that its 
molecules are actually larger than those of the common tobacco mosaic 
they weigh nearly as much as the giant molecules of the rabbit wart dis- 
ease, approximately 20,000,000. Now the strange finding of recent experi- 
ment is this: a tobacco plant suffering from the common form of the 
mosaic disease may suddenly change to the more virulent acuba form. 
Apparently something happens by which the smaller molecules of 17,000,- 
ooo weight attach other molecular groups to themselves to form particles 


of 20,000*000 weight, and these combinations take place between just the 
right groupings to produce the acuba effect. In a sense, it is a synthesis. 
Also it suggests the important property of individuality. Just as each gene, 
or at least certain genes, seems to carry an individual pattern to control the 
future development of its organism, so does the molecule of the mosaic 
disease possess a personality, a nature individual to its structure. . . . 

Oscar Riddle, of the Department of Genetics of the Carnegie Institution 
of Washington, noting some of these parallels, is inclined to believe that 
in one respect the gene represents a higher order of organization than the 
virus. He points to the teamwork of the genes in the chromosomes 1 as 
apparently an essential relationship. All the evidence goes to show that the 
gene must be in association with its fellow genes in order to duplicate, and 
Dr. Riddle doubts if a single gene alone can perform any function. Indeed, 
he questions if an isolated gene can be called alive which is precisely 
what Stanley questions of his crystalline protein. 

But this leads to another question. How "live" is alive? 

. . . Perhaps the nearest we can come to a definition is to say that life is 
a stage in the organization of matter. The ascent of life is a hierarchy of 
organizations continually becoming more complex and more versatile. 
And so with the ascent of matter, from the single electron or proton to 
the numerous and enormously complicated colony of electrical particles 
which make up the bacterium it too is a hierarchy of continually 
increasing complexity, of relationships, of organization. 

Protons and neutrons, with their encircling electrons, associate together 
to form atoms, but their organization is too primitive to permit any 
behavior recognizable as life. The atoms, in their turn, group to form 
molecules of simple compounds water, salts, carbon oxides but again 
the grouping is too limited to operate in ways that class as animate. From 
these simple molecules more complicated ones are synthesized in nature's 
unresting crucible, sugars and other carbohydrates, fats and more intricate 
hydrocarbons. And somehow, in the melee, atoms get joined together in 
the distinctive patterns known as catalysts, of which the enzymes are a 
special class. The primitive catalysts may fabricate the first amino acids. 
Out of these essential acids they build the first- proteins, simple ones at 
first. Proteins associate with other proteins, eventually they join as sub- 
groupings of larger molecules to form what we imagine to be the first 
genes, and chains of these giant molecules line up or interweave and inter- 
link as chromosomes. And so specialization develops, coordination evolves, 

a See Scheinfeld. 


the ability to duplicate the pattern, to divide, to multiply, to enter into a 
dynamic equilibrium of continually moving material and forces life! 

Just where life first appears in this supposed sequence is beyond charting. 
But perhaps it is not far amiss to think of the turning point as being 
reached with the emergence of the protein-building catalyst. The gene 
may be the most primitive living unit. The virus may be the most primitive 
predator on life. But the presumption is strong that neither of these organ- 
izations antedates the selective, assembling, organizing presence of the 
enzyme. The enzyme may not be life, but it seems to be a precursor of 
life. And whenever it becomes active may be the place where life begins. 



On Being the Right Size 


From Possible Worlds 

-** different animals are differences of size, but for some reason the 
zoologists have paid singularly little attention to them. In a large text- 
book of zoology before me I find no indication that the eagle is larger 
than the sparrow, or the hippopotamus bigger than the hare, though 
some grudging admissions are made in the case of the mouse and the 
whale. But yet it is easy to show that a hare could not be as large as a 
hippopotamus, or a whale as small as a herring. For every type of animal 
there is a most convenient size, and a large change in size inevitably car- 
ries with it a change of form. 

Let us take the most obvious of possible cases, and consider a giant man 
sixty feet high about the height of Giant Pope and Giant Pagan in the 
illustrated Pilgrim's Progress of my childhood. These monsters were not 
only ten times as high as Christian, but ten times as wide and ten times as 
thick, so that their total weight was a thousand times his, or about eighty 
to ninety tons. Unfortunately the cross sections of their bones were only 
a hundred times those of Christian, so that every square inch of giant 
bone had to support ten times the weight borne by a square inch of 
human bone. As the human thigh-bone breaks under about ten times the 
human weight, Pope and Pagan would have broken their thighs every 
time they took a step. This was doubtless why they were sitting down in 
the picture I remember. But it lessens one's respect for Christian and Jack 
the Giant Killer. 

To turn to zoology, suppose that a gazelle, a graceful little creature 
with long thin legs, is to become large, it will break its bones unless it 
does one of two things. It may make its legs short and thick, like the 
rhinoceros, so that every pound of weight has still about the same area 



of bone to support it. Or it can compress its body and stretch out its legs 
obliquely to gain stability, like the giraffe. I mention these two beasts 
because they happen to belong to the same order as the gazelle, and both 
are quite successful mechanically, being remarkably fast runners. 

Gravity, a mere nuisance to Christian, was a terror to Pope, Pagan, and 
Despair. To the mouse and any smaller animal it presents practically no 
dangers. You can drop a mouse down a thousand-yard mine shaft; and, 
on arriving at the bottom, it gets a slight shock and walks away, provided 
that the ground is fairly soft. A rat is killed, a man is broken, a horse 
splashes. For the resistance presented to movement by the air is propor- 
tional to the surface of the moving object. Divide an animal's length, 
breadth, and height each by ten; its weight is reduced to a thousandth, 
but its surface only to a hundredth. So the resistance to falling in the 
case of the small animal is relatively ten times greater than the driving 

An insect, therefore, is not afraid of gravity; it can fall without danger, 
and can cling to the ceiling with remarkably little trouble. It can go in for 
elegant and fantastic forms of support like that of the daddy-longlegs. But 
there is a force which is as formidable to an insect as gravitation to a 
mammal. This is surface tension. A man coming out of a bath carries 
with him a film of water of about one-fiftieth of an inch in thickness. 
This weighs roughly a pound. A wet mouse has to carry about its own 
weight of water. A wet fly has to lift many times its own weight and, as 
everyone knows, a fly once wetted by water or any other liquid is in a 
very serious position indeed. An insect going for a drink is in as great 
danger as a man leaning out over a precipice in search of food. If it once 
falls into the grip of the surface tension of the water that is to say, gets 
wet it is likely to remain so until it drowns. A few insects, such as water- 
beetles, contrive to be unwettable; the majority keep well away from their 
drink by means of a long proboscis. 

Of course tall land animals have other difficulties. They have to pump 
their blood to greater heights than a man, and therefore, require a larger 
blood pressure and tougher blood-vessels. A great many men die from 
burst arteries, especially in the brain, and this danger is presumably still 
greater for an elephant or a giraffe. But animals of all kinds find difficul- 
ties in size for the following reason. A typical small animal, say a micro- 
scopic worm or rotifer, has a smooth skin through which all the oxygen 
it requires can soak in, a straight gut with sufficient surface to absorb its 
food, and a single kidney. Increase its dimensions tenfold in every direc- 
tion, and its weight is increased a thousand times, so that if it is to use its 
muscles as efficiently as its miniature counterpart, it will need a thousand 


times as much food and oxygen per day and will excrete a thousand 
times as much of waste products. 

Now if its shape is unaltered its surface will be increased only a 
hundredfold, and ten times as much oxygen must enter per minute 
through each square millimetre of skin, ten times as much food through 
each square millimetre of intestine. When a limit is reached to their 
absorptive powers their surface has to be increased by some special 
device. For example, a part of the skin may be drawn out into tufts to 
make gills or pushed in to make lungs, thus increasing the oxygen- 
absorbing surface in proportion to the animal's bulk. A man, for example, 
has a hundred square yards of lung. Similarly, the gut, instead of being 
smooth and straight, becomes coiled and develops a velvety surface, and 
other organs increase in complication. The higher animals are not larger 
than the lower because they are more complicated. They are more com- 
plicated because they are larger. Just the same is true of plants. The 
simplest plants, such as the green algae growing in stagnant water or on 
the bark of trees, are mere round cells. The higher plants increase their 
surface by putting out leaves and roots. Comparative anatomy is largely 
the story of the struggle to increase surface in proportion to volume. 

Some of the methods of increasing the surface are useful up to a point, 
but not capable of a very wide adaptation. For example, while vertebrates 
carry the oxygen from the gills or lungs all over the body in the blood, 
insects take air directly to every part of their body by tiny blind tubes 
called tracheae which open to the surface at many different points. Now, 
although by their breathing movements they can renew the air in the 
outer part of the tracheal system, the oxygen has to penetrate the finer 
branches by means of diffusion. Gases can diffuse easily through very 
small distances, not many times larger than the average length travelled 
by a gas molecule between collisions with other molecules. But when such 
vast journeys from the point of view of a molecule as a quarter of an 
inch have to be made, the process becomes slow. So the portions of an in- 
sect's body more than a quarter of an inch from the air would always be 
short of oxygen. In consequence hardly any insects are much more than 
half an inch thick. Land crabs are built on the same general plan as insects, 
but are much clumsier. Yet like ourselves they carry oxygen around in 
their blood, and are therefore able to grow far larger than any insects. If 
the insects had hit on a plan for driving air through their tissues instead of 
letting it soak in, they might well have become as large as lobsters, though 
other considerations would have prevented them from becoming as 
large as man. 

Exactly the same difficulties attach to flying. It is an elementary principle 


of aeronautics that the minimum speed needed to keep an aeroplane of a 
given shape in the air varies as the square root of its length. If its linear 
dimensions are increased four times, it must fly twice as fast. Now the 
power needed for the minimum speed increases more rapidly than the 
weight of the machine. So the larger aeroplane, which weighs sixty-four 
times as much as the smaller, needs one hundred and twenty-eight times 
its horsepower to keep up. Applying the same principles to the birds, we 
find that the limit to their size is soon reached. An angel whose muscles 
developed no more power weight for weight than those of an eagle or a 
pigeon would require a breast projecting for about four feet to house the 
muscles engaged in working its wings, while to economize in weight, its 
legs would have to be reduced to mere stilts. Actually a large bird such as 
an eagle or kite does not keep in the air mainly by moving its wings. It is 
generally to be seen soaring, that is to say balanced on a rising column of 
air. And even soaring becomes more and more difficult with increasing 
size. Were this not the case eagles might be as large as tigers and as 
formidable to man as hostile aeroplanes. 

But it is time that we pass to some of the advantages of size. One of the 
most obvious is that it enables one to keep warm. All warm-blooded 
animals at rest lose the same amount of heat from a unit area of skin, for 
which purpose they need a food-supply proportional to their surface and 
not to their weight. Five thousand mice weigh as much as a man. Their 
combined surface and food or oxygen consumption are about seventeen 
times a man's. In fact a mouse eats about one quarter its own weight of 
food every day, which is mainly used in keeping it warm. For the same 
reason small animals cannot live in cold countries. In the arctic regions 
there are no reptiles or amphibians, and no small mammals. The smallest 
mammal in Spitzbergen is the fox. The small birds fly away in winter, 
while the insects die, though their eggs can survive six months or more 
of frost. The most successful mammals are bears, seals, and walruses. 

Similarly, the eye is a rather inefficient organ until it reaches a large 
size. The back of the human eye on which an image of the outside world 
is thrown, and which corresponds to the film of a camera, is composed of 
a mosaic of 'rods and cones' whose diameter is little more than a length 
of an average light wave. Each eye has about a half a million, and for 
two objects to be distinguishable their images must fall on separate rods 
or cones. It is obvious that with fewer but larger rods and cones we should 
see less distinctly. If they were twice as broad two points would have to 
be twice as far apart before we could distinguish them at a given distance. 
But if their size were diminished and their number increased we should 
see no better. For it is impossible to form a definite image smaller than a 


wave-length of light. Hence a mouse's eye is not a small-scale model of a 
human eye. Its rods and cones are not much smaller than ours, and there- 
fore there are far fewer of them. A mouse could not distinguish one 
human face from another six feet away. In order that they should be of 
any use at all the eyes of small animals have to be much larger in pro- 
portion to their bodies than our own. Large animals on the other hand 
only require relatively small eyes, and those of the whale and elephant 
are little larger than our own. 

For rather more recondite reasons the same general principle holds true 
of the brain. If we compare the brain-weights of a set of very similar 
animals such as the cat, cheetah, leopard, and tiger, we find that as we 
quadruple the body-weight the brain-weight is only doubled. The larger 
animal with proportionately larger bones can economize on brain, eyes, 
and certain other organs. 

Such are a very few of the considerations which show that for every 
type of animal there is an optimum size. Yet although Galileo demon- 
strated the contrary more than three hundred years ago, people still 
believe that if a flea were as large as a man it could jump a thousand feet 
into the air. As a matter of fact the height to which an animal can jump 
is more nearly independent of its size than proportional to it. A flea can 
jump about two feet, a man about five. To jump a given height, if we 
neglect the resistance of the air, requires an expenditure of energy pro- 
portional to the jumper's weight. But if the jumping muscles form a con- 
stant fraction of the animal's body, the energy developed per ounce of 
muscle is independent of the size, provided it can be developed quickly 
enough in the small animal. As a matter of fact an insect's muscles, al- 
though they can contract more quickly than our own, appear to be less 
efficient; as otherwise a flea or grasshopper could rise six feet into the air. 


Parasitism and Degeneration 


From Evolution and Animal Life 

degeneration, cannot be very rigidly defined. To prey upon the bodies 
of other animals is the common habit of many creatures. If the animals 
which live in this way are free, chasing or lying in wait for or snaring 
their prey, we speak of them in general as predatory animals. But if they 
attach themselves to the body of their prey or burrow into it, and are 
carried about by it, live on or in it, then we call them parasites. And the 
difference in habit between a lion and an intestinal worm is large enough 
and marked enough to make very clear to us what is meant when we 
speak of one as predatory and the other as a parasite. But how shall we 
class the lamprey, that swims about until it finds a fish to which it clings, 
while sucking away its blood ? It lives mostly free, hunting its prey, clinging 
to it for a while, and is carried about by it. Closely related to the lampreys 
are the hag fishes, marine eel-like fishes that attach themselves by a sucker- 
like mouth to living fishes and gradually scrape and eat their way into the 
abdominal cavity of the host. These "hags" or "borers" approach more 
nearly to the condition of an internal parasite than any other vertebrate. 
And what about the flea? In its immature life it lives as a white grub or 
larva in the dust of cracks and crevices, of floors and cellars and heaps of 
debris; here it pupates, and finally changes into the active leaping blood- 
sucking adult which finds its way to the body of some mammal and clings 
there sucking blood. But it can jump off and hunt other prey; it leaves the 
host body entirely to lay its eggs, and yet it feeds as a parasite, at least it 
conforms to the definition of parasite in the essential fact of being carried 
about on or in the host body, while feeding at the host's expense. . . . 

The bird lice which infest the bodies of all kinds of birds and are found 
especially abundant on domestic fowls, live upon the outside of the bodies 



of their hosts, feeding upon the feathers and dermal scales. They are 
examples of external parasites. Other examples are fleas and ticks, and the 
crustaceans called fish lice and whale lice, which are attached to marine 
animals. On the other hand, almost all animals are infested by certain 
parasitic worms which live in the alimentary canal, like the tapeworm, or 
imbedded in the muscles, like the trichina. These are examples of internal 
parasites. Such parasites belong mostly to the class of worms, and some 
of them are very injurious, sucking the blood from the tissues of the host, 
while others feed solely on the partly digested food. There are also para- 
sites that live partly within and partly on the outside of the body, like the 
Sacculina, which lives on various kinds of crabs. The body of the Sacculina 
consists of a soft sac which lies on the outside of the crab's body, and of a 
number of long, slender rootlike processes which penetrate deeply into the 
crab's body, and take up nourishment from within. The Sacculina is itself 
a crustacean or crablike creature. The classification of parasites as external 
and internal is purely arbitrary, but it is often a matter of convenience. 

Some parasites live for their whole lifetime on or in the body of the 
host, as is the case with the bird lice. Their eggs are laid on the feathers 
of the bird host; the young when hatched remain on the bird during 
growth and development, and the adults only rarely leave the body, 
usually never. These may be called permanent parasites. On the other 
hand, fleas leap off or on a dog apparently as caprice dictates; or, as in 
other cases, the parasite may pass some definite part of its life as a free 
nonparasitic organism, attaching itself, after development, to some animal, 
and remaining there for the rest of its life. These parasites may be called 
temporary parasites. But this grouping or classification, like that of the 
external and internal parasites, is simply a matter of convenience, and does 
not indicate at all any blood relationship among the members of any one 

Some parasites are so specialized in habit and structure that they are 
wholly unable to go through their life history, or to maintain themselves, 
except in a single fixed way. They are dependent wholly on one particular 
kind of host, or on a particular series of hosts, part of their ^ life being 
passed in one and another part in one or more other so-called intermediate 
hosts. These parasitic species are called obligate parasites, while others with 
less definite, more flexible requirements in regard to their mode of devel- 
opment and life are called facultative parasites. These latter may indeed 
be able to go through life as free-living, nonparasitic animals, although, 
with opportunity, they live parasitically. 

In nearly all cases the body of a parasite is simpler in structure than the 
body of other animals which are closely related to the parasite that is, 


animals that live parasitically have simpler bodies than animals that live 
free active lives, competing for food with the other animals about them. 
This simplicity is not primitive, but results from the loss or atrophy of the 
structures which the mode of life renders useless. Many parasites are 
attached firmly to their host, and do not move about. They have no need 
of the power of locomotion. They are carried by their host. Such parasites 
are usually without wings, legs, or other locomotory organs. Because they 
have given up locomotion they have no need of organs of orientation, 
those special sense organs like eyes and ears and feelers which serve to 
guide and direct the moving animal; and most nonlocomotory parasites 
will be found to have no eyes, nor any of the organs of special sense 
which are accessory to locomotion and which serve for the detection of 
food or of enemies. Because these important organs, which depend for 
their successful activity on a highly organized nervous system, are lacking, 
the nervous system of parasites is usually very simple and undeveloped. 
Again, because the parasite usually has for its sustenance the already 
digested highly nutritious food elaborated by its host, most parasites have 
a very simple alimentary canal, or even no alimentary canal at all. Finally, 
as the fixed parasite leads a wholly sedentary and inactive life, the breaking 
down and rebuilding of tissue in its body go on very slowly and in mini- 
mum degree, and there is no need of highly developed respiratory and 
circulatory organs, so that most fixed parasites have these systems of organs 
in simple condition. Altogether the body of a fixed, permanent parasite 
is so simplified and so wanting in all those special structures which char- 
acterize the higher, active, complex animals, that it often presents a very 
different appearance from those animals with which we know it to be 
nearly related. 

The simplicity of parasites does not indicate that they belong to the 
groups of primitive simple animals. Parasitism is found in the whole 
range of animal life, from primitive to highest, although the vertebrate 
animals include very few parasites and these of little specialization of 
habit. But their simplicity is something that has resulted from their mode 
of life. It is the result of a change in the body structure which we can 
often trace in the development of the individual parasite. Many parasites 
in their young stages are free, active animals with a better or more complex 
body than they possess in their fully developed or adult stage. The sim- 
plicity of parasites is the result of degeneration a degeneration that has 
been brought about by their adoption of a sedentary, non-competitive 
parasitic life. And this simplicity of degeneration, and the simplicity of 
primitiveness should be sharply distinguished. Animals that are primitively 
simple have had only simple ancestors; animals that are simple by 


degeneration often have had highly organized, complex ancestors. And 
while in the life history or development of a primitively simple animal all 
the young stages are simpler than the adult, in a degenerate animal the 
young stages may be, and usually are, more complex and more highly 
organized than the adult stage. 

In the few examples of parasitism (selected from various animal groups) 
that are described in the following pages all these general statements are 

In the intestines of crayfishes, centipedes, and several kinds of insects 
may often be found certain one-celled animals (Protozoa) which are living 
as parasites. Their food, which they take into their minute body by absorp- 
tion, is the intestinal fluid in which they lie. These parasitic Protozoa 
belong to the genus Gregarina. . . . There are, besides Gregarina, many 
other parasitic one-celled animals, several kinds living inside the cells of 
their host's body. Several kinds of these have been proved to be the causal 
agents of serious human diseases. Conspicuous among these are the minute 
parasitic Sporozoa which are the actual cause of the malarial and similar 
fevers that rack ihe human body in nearly all parts of the world. . . r 

When a mosquito (at least of a certain kind) sucks blood from a 
malarial patient the blood parasites are of course taken in also and 
deposited in the stomach where digestion of the blood begins. Now when 
the zygotes [resting egg cells] are formed in the mosquito's stomach they 
do not remain lying in the stomach cavity but move to the wall of the 
stomach and partially penetrate it. As many as five hundred zygotes have 
been found in the stomach walls of a single mosquito. The zygote now 
increases rapidly in size, becoming a perceptible nodule on the outer side 
of the stomach wall, but soon its nucleus and protoplasm begin to break 
up by repeated division (the parts all being held together, however, in the 
wall of the zygote), and by the end of the twelfth or fourteenth day the 
zygote's protoplasm may have become divided into ten thousand minute 
sporozoites. The zygote wall now breaks down, thus releasing the thou- 
sands of active little sporozoites into the general body cavity of the mos- 
quito. This cavity is filled with flowing blood plasm insects 'do not have 
a closed but an almost completely open circulatory system and swim- 
ming about in this plasm the sporozoites soon make their way forward 
and into the salivary glands of the mosquito. Now when the insect pierces 
a human being to suck blood, it injects a certain amount of salivary fluid 
into the wound (presumably to keep the blood from clotting at the punc- 
ture) and with this fluid go many of the sporozoites. Thus a new infection 
f malaria is made. The sporozoites may lie in the salivary glands for 
several weeks, and so for the whole time from twelve to fourteen days 


after the mosquito has become infected with the malarial parasite by 
sucking blood from a malarial patient until the sporozoites in the salivary 
glands finally die, it is a means of the dissemination of the disease. There 
can be no malaria without mosquitoes to propagate and disseminate it, and 
yet no mosquitoes can propagate and disseminate malaria without having 
access to malarial patients. . . . 

In the great branch or phylum of flatworms, that group of animals which 
of all the principal animal groups is widest in its distribution, perhaps a 
majority of the species are parasites. Instead of being the exception, the 
parasitic life is the rule among these worms. Of the three classes into which 
the flatworms are divided, almost all of the members of two of the classes 
are parasites. The common tapeworm, which lives parasitically in the 
intestine of man, is a good example of one of these classes. It has the form 
of a narrow ribbon, which may attain the length of several yards, attached 
at one end to the wall of the intestine, the remainder hanging freely in the 
interior. Its body is composed of segments or serially arranged parts, of 
which there are about eight hundred and fifty altogether. It has no mouth 
nor alimentary canal. It feeds simply by absorbing into its body, through 
the surface, the nutritious, already digested liquid food in the intestine. 
There are no eyes nor other special sense organs, nor any organs of locomo- 
tion. The body is very degenerate. The life history of the tapeworm is 
interesting, because of the necessity of two hosts for its completion. The 
eggs of the tapeworm pass from the intestine with the excreta, and must 
be taken into the body of some other animal in order to develop. In the 
case of one of the several species of tapeworms that infest man, this other 
host must be the pig. In the alimentary canal of the pig the young tape- 
worm develops and later bores its way through the walls of the canal and 
becomes imbedded in the muscles. There it lies, until it finds its way into 
the alimentary canal of man by his eating the flesh of the pig. In the 
intestine of man the tapeworm continues to develop until it becomes full 
grown. . . . 

Another group of animals, many of whose members are parasites, are 
the roundworms or threadworms. The free-living roundworms are active, 
well-organized animals, but the parasitic kinds all show a greater or less 
degree of degeneration. One of the most terrible parasites of man is a 
roundworm called Trichina spiralis. It is a minute worm, from one to 
three millimeters long, which in its adult condition lives in the intestine 
of man or of the pig or other mammals. The young are born alive and 
bore through the walls of the intestine. They migrate to the voluntary 
muscles of the hosts, especially those of the limbs and back, and here each 
worm coils itself up in a muscle fiber and becomes inclosed in a spindle- 


shaped cyst or cell. A single muscle may be infested by hundreds of thou- 
sands of these minute worms. It has been estimated that fully one hun- 
dred million encysted worms may exist in the muscles of a "trichinized" 
human body. The muscles undergo more or less degeneration, and the 
death of the host may occur. It is necessary, for the further development of 
the worms, that the flesh of the host be eaten by another mammal, as the 
flesh of the pig by man, or the flesh of man by a pig or rat. The Trichina 
in the alimentary canal of the new host develop into active adult worms 
and produce new young. 

In the Yellowstone Lake the trout are infested by the larvae or young 
of a roundworm which reach a length of twenty inches, and which are 
often found stitched, as it were, through the viscera and the muscles of 
the fish. The infested trout become feeble and die, or are eaten by the 
pelicans which fish in this lake. In the alimentary canal of the pelican the 
worms become adult, and parts of the worms containing eggs escape from 
the alimentary canal with the excreta. These portions of worms are eaten 
by the trout, and the eggs give birth to new worms which develop in 
the bodies of the fish with disastrous effects. It is estimated that for each 
pelican in Yellowstone Lake over five million eggs of the parasitic worms 
are discharged into the lake. 

The young of various carnivorous animals are often infested by one 
of the species of roundworms called "pup worms." Recent investigations 
show that thousands of the young or pup fur seals are destroyed each 
year by these parasites. The eggs of the worm lie through the winter in 
the sands of the breeding grounds of the fur seal. The young receive them 
from the fur of the mother and the worm develops in the upper intes- 
tine. It feeds on the blood of the young seal, which finally dies from 
anaemia. On the sand beaches of the seal islands in Bering Sea there are 
every year thousands of dead seal pups which have been killed by this 
parasite. On the rocky rookeries, the young seals are not affected by this 

Among the more highly organized animals the results of a parasitic 
life, in degree of structural degeneration, can be more readily seen. A 
well-known parasite, belonging to the Crustacea the class of shrimps, 
crabs, lobsters, and crayfishes is Sacculina. The young Sacculina is an 
active, free-swimming larva much like a young prawn or young crab. 
But the adult bears absolutely no resemblance to such a typical crus- 
tacean as a crayfish or crab. The Sacculina after a short period of inde- 
pendent existence attaches itself to the abdomen of a crab, and there 
completes its development while living as a parasite. In its adult condi- 
tion it is simply a great tumorlike sac, bearing many delicate rootlike 


suckers which penetrate the body o the crab host and absorb nutriment. 
The Sacculina has no eyes, no mouth parts, no legs, or other appendages, 
and hardly any of the usual organs except reproductive organs. 

Other parasitic Crustacea, as the numerous kinds of fish lice which 
live attached to the gills or to other parts of fish, and derive all their 
nutriment from the body of the fish, show various degrees of degenera- 
tion. With some of these fish lice the female, which looks like a puffed- 
out worm, is attached to the fish or other aquatic animal, while the 
male, which is perhaps only a tenth of the size of the female, is per- 
manently attached to the female, living parasitically on her. 

Among the insects there are many kinds that live parasitically for 
part of their lives, and not a few that live as parasites for their whole 
lives. The true sucking lice and the bird lice live for their whole lives 
as external parasites on the bodies of their host, but they are not fixed 
that is, they retain their legs and power of locomotion, although they have 
lost their wings through degeneration. The eggs of the lice are deposited 
on the hair of the mammal or bird that serves as host; the young hatch 
and immediately begin to live as parasites, either sucking the blood or 
feeding on the hair or feathers of the host. . . . The ichneumon flies are 
parasites of other insects, especially of the larvae of beetles and moths and 
butterflies. In fact, the ichneumon flies do more to keep in check die in- 
crease of injurious and destructive caterpillars than do all our artificial 
remedies for these insect pests. . . . 

One of the most remarkable ichneumon flies is Thalessa, which has a 
very long, slender, flexible ovipositor, or egg-laying organ. An insect 
known as the pigeon horntail deposits its eggs, by means of a strong, 
piercing ovipositor, half an inch deep in the trunk wood of growing 
tree. The young or larval pigeon horntail is a 'soft-bodied white grub, 
which bores deeply into the trunk of the tree, filling up the burrow 
behind it with small chips. The Thalessa is a parasite of the pigeon horn- 
tail, and "when a female Thalessa finds a tree infested by the pigeon horn- 
tail, she selects a place which she judges is opposite a pigeon horntail 
burrow, and, elevating her long ovipositor in a loop over her back, with 
its tip on the bark of the tree, she makes a derrick out of her body and 
proceeds with great skill and precision to drill a hole into the tree. When 
the pigeon horntail burrow is reached she deposits an egg in it. The 
larva that hatches from this egg creeps along this burrow until it reaches 
its victim, and then fastens itself to the horntail larva, which it destroys 
by sucking its blood. The larva of Thalessa, when full grown, changes 
to a pupa within the burrow of its host, and the adult gnaws a hole out 


through the bark i it does not find the hole already made by the pigeon 

. . . Almost all of the mites and ticks, animals allied to the spiders, live 
parasitically. Most of them live as external parasites, sucking the blood 
of their host, but some live underneath the skin like the itch mites, 
which cause, in man, the disease known as the itch. 

Among the vertebrate animals there are not many examples of true 
parasitism. The hagfishes or borers have been already mentioned. These 
are long and cylindrical, eel-like creatures, very slimy and very low in 
structure. The mouth is without jaws, but forms a sucking disk, by which 
the hagfish attaches itself to the body of some other fish. By means of 
the rasping teeth on its tongue, it makes a round hole through the skin, 
usually at the throat. It then devours all the muscular substance of the 
fish, leaving the viscera untouched. When the fish finally dies it is a 
mere hulk of skin, scales, bones, and viscera, nearly all the muscle being 
gone. Then the hagfish slips out and attacks another individual. 

The lamprey, another low fish, in similar fashion feeds leechlike on 
the blood of other fishes, which it obtains by lacerating the flesh with 
its rasp-like teeth, remaining attached by the round sucking disk of 
its mouth. 

Certain birds, as the cowbird and the European cuckoo, have a para- 
sitic habit, laying their eggs in the nests of other birds, leaving their 
young to be hatched and reared by their unwilling hosts. 

We may also note that parasitism and consequent structural degenera- 
tion are not at all confined to animals. Many plants are parasites and show 
marked degenerative characteristics. The dodder is a familiar example, 
clinging to living green plants and thrusting its haustoria or rootlike suck- 
ers into their tissue to draw from them already elaborated nutritive sap. 
Many fungi like the rusts of cereals, the mildew of roses, etc., are parasitic. 
Numerous plants, too, are parasites, not on other plants, but on animals. 
Among these are the hosts of bacteria (simplest of the one-celled plants) 
that swarm in the tissues of all animals, some of which are causal agents 
of some of the worst of human and animal diseases (as typhoid fever, 
diphtheria, and cholera in man, anthrax in cattle). There are also many 
more highly organized fungi that live in and on the bodies of insects, 
often killing them by myriads. One of the great checks to the ravages of 
the corn- and wheat-infesting chinch bug of the Mississippi Valley is a 
parasitic fungus. In the autumn, house flies may often be seen dead against 
a windowpane surrounded by a delicate ring or halo of white. This ring 
is composed of spores of a fungus which has grown through all the tissue* 


of the fly while alive, finally resulting in its death. The spores serve to 
inoculate other flies that may come near. 

Just as in animals, so in plants; parasitic kinds, especially among the 
higher groups as the flowering plants, often show marked degeneration. 
Leaves may be reduced to mere scales, roots are lost, and the water- 
conducting tissues greatly reduced. This degeneration in plants naturally 
affects primarily those parts which in the normal plant are devoted 
to the gathering and elaboration of inorganic food materials, namely, 
the leaves and stems and roots. The flowers or reproductive organs 
usually retain, in parasites, all of their high development. 

While parasitism is the principal cause of degeneration of animals, 
other causes may be also concerned. Fixed animals or animals leading 
inactive or sedentary lives, also become degenerate, even when no para- 
sitism is concerned. . . . 

A barnacle is an example of degeneration through quiescence. The 
barnacles are crustaceans related most nearly to the crabs and shrimps. 
The young barnacle just from the egg is six-legged, free-swimming, much 
like a young prawn or crab, with single eye. In its next larval stage it 
has six pairs of swimming feet, two compound eyes, and two large 
antennae or feelers, and still lives an independent, free-swimming life. 
When it makes its final change to the adult condition, it attaches itself 
to some stone or shell, or pile or ship's bottom, loses its compound eyes 
and feelers, develops a protecting shell, and gives up all power of locomo- 
tion. Its swimming feet become changed into grasping organs, and it 
loses most of its outward resemblances to the other members of its class. 

Certain insects live sedentary or fixed lives. All the members of the 
family of scale insects, in one sex at least, show degeneration that has 
been caused by quiescence. One of these, called the red orange scale, is 
very abundant in Florida and California and in other orange-growing 
regions. The male is a beautiful, tiny, two-winged midge, but the female 
is a wingless, footless little sac without eyes or other organs of special 
sense, and lies motionless under a flat, thin, circular, reddish scale com- 
posed of wax and two or three cast skins of the insect itself. The insect 
has a long, slender, flexible, sucking beak, which is thrust into the leaf 
or stem or fruit of the orange on which the "scale bug" lives and through 
which the insect sucks the orange sap, which is its only food. It lays 
eggs or gives birth to young under its body, under the protecting wax 
scale, and dies. From the eggs hatch active little larval scale bugs with 
eyes and feelers and six legs. They crawl from under the wax scale and 
roam about over the orange tree. Finally, they settle down, thrust their 
sucking beak into the plant tissues, and cast their skin. The females lose 


at this molt their legs and eyes and feelers. Each becomes a mere motion- 
less sac capable only of sucking up sap and of laying eggs. The young 
males, however, lose their sucking beak and can no longer take food, 
but they gain a pair of wings and an additional pair of eyes. They fly 
about and fertilize the saclike females, which then molt again and secrete 
the thin wax scale over them. 

. . . Loss of certain organs may occur through other causes than para- 
sitism and a fixed life. Many insects live but a short time in their adult 
stage. May flies live for but a few hours or, at most, a few days. They 
do not need to take food to sustain life for so short a time, and so their 
mouth parts have become rudimentary and functionless or are entirely 
lost. This is true of some moths and numerous other specially short-lived 
insects. Among the social insects the workers of the termites and of the 
true ants are wingless, although they are born of winged parents, and 
are descendants of winged ancestors. The modification of structure de- 
pendent upon the division of labor among the individuals of the com- 
munity has taken the form, in the case of the workers, of a degeneration 
in the loss of the wings. Insects that live in caves are mostly blind; they 
have lost the eyes, whose function could not be exercised in the darkness 
of the cave. Certain island-inhabiting insects have lost their wings, flight 
being attended with too much danger. The strong sea breezes may at any 
time carry a flying insect oflf the small island to sea. Probably only those 
which do not fly much survive, and so by natural selection wingless 
breeds or species are produced. Finally, the body may be modified in color 
and shape so as to resemble some part of the environment, and thus the 
animal may be unperceived by its enemies. 

When we say that a parasitic or quiescent mode of life leads to or 
causes degeneration, we have explained the stimulus or the ultimate rea- 
son for the degenerative changes, but we have not shown just how 
parasitism or quiescence actually produces these changes. Degeneration or 
the atrophy and disappearance of organs or parts of a body is often said 
to be due to disuse. That is, the disuse of a part is believed by many 
naturalists to be the sufficient cause for its gradual dwindling and final 
loss. That disuse can so affect parts of a body during the lifetime of an 
individual is true. A muscle unused becomes soft and flabby and small. 
Whether the effects of such disuse can be inherited, however, is open 
to serious doubt. ... If not, some other immediate cause, or some other 
cause along with disuse, must be found. 

We are accustomed, perhaps, to think of degeneration as necessarily 
implying a disadvantage in life. A degenerate animal is considered to be 
not the equal of a nondegenerate animal, and this would be true if both 


kinds of animals had to face the same conditions of life. The blind, foot- 
less, simple, degenerate animal could not cope with the active, keen- 
sighted, highly organized nondegenerate in free competition. But free 
competition is exactly what the degenerate animal has nothing to do 
with. Certainly the Sacculina lives successfully; it is well adapted for its 
own peculiar kind of life. For the life of a scale insect, no better type of 
structure could be devised. A parasite enjoys certain obvious advantages 
in life, and even extreme degeneration is no drawback, but rather favors 
it in the advantageousness of its sheltered and easy life. As long as the 
host is successful in eluding its enemies and avoiding accident and injury, 
the parasite is safe. It needs to exercise no activity or vigilance of its own; 
its life is easy as long as its host lives. But the disadvantages of parasitism 
and degeneration are apparent also. The fate of the parasite is usually 
bound up with the fate of the host. When the enemy of the host crab 
prevails, the Sacculina goes down without a chance to struggle in its 
own defense. But far more important than the disadvantage in such 
particular or individual cases is the disadvantage of the fact that the 
parasite cannot adapt itself in any considerable degree to new conditions. 
It has become so specialized, so greatly modified and changed to adapt 
itself to the one set of conditions under which it now lives, it has gone so 
far in its giving up of organs and body parts, that if present conditions 
should change and new ones come to exist, the parasite could not adapt 
itself to them. The independent, active animal with all its organs and all 
its functions intact, holds itself, one may say, ready and able to adapi 
itself to any new conditions of life which may gradually come into exist- 
ence. The parasite has risked everything for the sake of a sure and easy 
life under the presently existing conditions. Change of conditions means 
its extinction. 


Flowering Earth 


From Flowering Earth 


into the coolness of a wood, is that its boughs close up behind us. 
We are escaped, into another room of life. The wood does not live as we 
live, restless and running, panting after flesh, and even in sleep tossing 
with fears. It is aloof from thoughts and instincts; it responds, but only 
to the sun and wind, the rock and the stream never, though you shout 
yourself hoarse, to propaganda, temptation, reproach, or promises. You 
cannot mount a rock and preach to a tree how it shall attain the kingdom 
of heaven. It is already closer to it, up there, than you will grow to be. 
And you cannot make it see the light, since in the tree's sense you are 
blind. You have nothing to bring it, for all the forest is self-sufficient; if 
you burn it, cut, hack through it with a blade, it angrily repairs the 
swathe with thorns and weeds and fierce suckers. Later there are good 
green leaves again, toiling, adjusting, breathing forgetting you. 

For this green living is the world's primal industry; yet it makes no 
roar. Waving its banners, it marches across the earth and the ages, without 
dust around its columns. I do not hold that all of that life is pretty; it is 
not, in purpose, sprung for us, and moves under no compulsion to please. 
If ever you fought with thistles, or tried to pull up a cattail's matted root- 
stocks, you will know how plants cling to their own lives and defy you. 
The pond-scums gather in the cistern, frothing and buoyed with their 
own gases; the storm waves fling at your feet upon the beach the limp 
sea-lettuce wrenched from its submarine hold reminder that there too, 
where the light is filtered and refracted, there is life still to intercept and 
net and by it proliferate. Inland from the shore I look and see the coastal 
ranges clothed in chaparral dense shrubbery and scrubbery, close-fisted, 
intricately branched, suffocating the rash rambler in the noon heat with 



its pungency. Beyond, on the deserts, under a fierce sky, between the 
harsh lunar ranges of unweathered rock, life still, somehow, fights its 
way through the year, with thorn and succulent cell and indomitable 

Between such embattled life and the Forest of Arden, with its ancient 
beeches and enchanter's nightshade, there is no great biologic difference. 
Each lives by the cool and cleanly and most commendable virtue of being 
green. And though that is not biological language, it is the whole story in 
two words. So that we ought not speak of getting at the root of a matter, 
but of going back to the leaf of things. The orator who knows the way 
to the country's salvation and does not know that the breath of life he 
draws was blown into his nostrils by green leaves, had better spare his 
breath. And before anyone builds a new state upon the industrial prole- 
tariat, he will be wisely cautioned to discover that the source of all 
wealth is the peasantry of grass. 

The reason for these assertions which I do not make for metaphorical 
effect but maintain quite literally is that the green leaf pigment, called 
chlorophyll, is the one link between the sun and life; it is the conduit 
of perpetual energy to our own frail organisms. 

For inert and inorganic elements water and carbon dioxide of the 
air, the same that we breathe out as a waste chlorophyll can synthesize 
with the energy of sunlight. Every day, every hour of all the ages, as 
each continent and, equally important, each ocean rolls into sunlight, 
chlorophyll ceaselessly creates. Not figuratively, but literally, in the grand 
First Chapter Genesis style. One instant there are a gas and water, as 
lifeless as the core of earth or the chill of space; and the next they are 
become living tissue mortal yet genitive, progenitive, resilient with all 
the dewy adaptability of flesh, ever changing in order to stabilize some 
unchanging ideal of form. Life, in short, synthesized, plant-synthesized, 
light-synthesized. Botanists say photosynthesized. So that the post-Biblical 
synthesis of life is already a fact. Only when man has done as much, may 
he call himself the equal of a weed. 

Plant life sustains the living world; more precisely, chlorophyll does 
so, and where, in the vegetable kingdom, there is not chlorophyll or some- 
thing closely like it, then that plant or cell is a parasite no better, in vital 
economy, than a mere animal or man. Blood, bone and sinew, all flesh 
is grass. Grass to mutton, mutton to wool, wool to the coat on my back 
it runs like one of those cumulative nursery rhymes, the wealth and 
diversity of our material life accumulating from the primal fact of chloro- 
phyll's activity. The roof of my house, the snapping logs upon the 
hearth, the desk where I write, are my imports from the plant kingdom. 


But the whole of modern civilization is based upon a whirlwind spending 
of the plant wealth long ago and very slowly accumulated. For, funda- 
mentally, and away back, coal and oil, gasoline and illuminating gas had 
green origins too. With the exception of a small amount of water power, 
a still smaller of wind and tidal mills, the vast machinery of our complex 
living is driven only by these stores of plant energy. 

We, then, the animals, consume those stores in our restless living. 
Serenely the plants amass them. They turn light's active energy to food, 
which is potential energy stored for their own benefit. Only if the daisy 
is browsed by the cow, the maple leaf sucked of its juices by an insect, 
will that green leaf become of our kind. So we get the song of a bird at 
dawn, the speed in the hoofs of the fleeing deer, the noble thought in 
the philosopher's mind. So Plato's Republic was builded on leeks and 

Animal life lives always in the red; the favorable balance is written 
on the other side of life's page, and it is written in chlorophyll. All else 
obeys the thermodynamic law that energy forever runs down hill, is 
lost and degraded. In economic language, this is the law of diminishing 
returns, and it is obeyed by the cooling stars as by man and all the 
animals. They float down its Lethe stream. Only chlorophyll fights up 
against the current. It is the stuff in life that rebels at death, that has 
never surrendered to entropy, final icy stagnation. It is the mere cobweb 
on which we are all suspended over the abyss. 

And what then is this substance which is not itself alive but is made 
by life and makes life, and is never found apart from life? 

I remember the first time I ever held it, in the historic dimness of the 
old Agassiz laboratories, pure, in my hands. My teacher was an owl-eyed 
master, with a chuckling sense of humor, who had been trained in the 
greatest laboratory in Germany, and he believed in doing the great things 
first. So on the first day of his course he set us to extracting chlorophyll, 
and I remember that his eyes blinked amusement behind his glasses, 
because when he told us all to go and collect green leaves and most went 
all the way to the Yard for grass, I opened the window and stole from 
a vine upon the wall a handful of Harvard's sacred ivy. 

We worked in pairs, and my fellow student was a great-grand-nephew 
or something of the sort, of Elias Fries, the founder of the study of fungi. 
Together we boiled the ivy leaves, then thrust them in alcohol. After a 
while it was the leaves which were colorless while the alcohol had become 
green. We had to dilute this extract with water, and then we added ben- 
zol, because this will take the chlorophyll away from the alcohol which, 
for its part, very conveniently retains the yellow pigments also found 


in leaves. This left us with a now yellowish alcohol and, floating on top 
of it, a thick green benzol; you could simply decant the latter carefully 
off into a test tube, and there you had chlorophyll extract, opaque, 
trembling, heavy, a little viscous and oily, and smelling, but much too 
rankly, like a lawn-mower's blades after a battle with rainy grass. 

Then, in a darkened room where beams from a spectroscope escaped 
in painful darts of light as from the cracks in an old-fashioned magic 
lantern, we peered at our extracted chlorophyll through prisms. Just as 
in a crystal chandelier the sunlight is shattered to a rainbow, so in the 
spectroscope light is spread out in colored bands a long narrow ribbon, 
sorting the white light by wave lengths into its elemental parts. And the 
widths, the presence or the absence, of each cross-band on the ribbon, 
tell the tale of a chemical element present in the spectrum, much as the 
bands on a soldier's insignial ribbon show service in Asia, in the tropics, 
on the border, in what wars. When the astronomer has fixed spectroscope 
instead of telescope upon a distant star, he reads off the color bands as 
easily as one soldier reads another's, and will tell you whether sodium 
or oxygen, helium or iron is present. 

Just so our chlorophyll revealed its secrets. The violet and blue end of 
the spectrum was almost completely blacked out. And that meant that 
chlorophyll absorbed and used these high-frequency waves. So, too, the 
red and orange were largely obliterated, over at the right hand side of 
our tell-tale bar. It was the green that came through clearly. So we call 
plants green because they use that color least. It is what they reject as 
fast as it smites the upper cells; it is what they turn back, reflect, flash 
into our grateful retinas. 

It was only routine in a young botanist's training to make an extraction 
and spectrum analysis of chlorophyll. My student friends over in the 
chemistry laboratories were more excited than I about it. They were 
working under Conant, before he became president of Harvard and had 
to sneak into his old laboratory at night with a key he still keeps. For 
chlorophyll was Conant's own problem. His diagram of its structure, 
displayed to ine by his students, was closely worked over with symbols 
and signs, unfolded to something like the dimensions of a blue print of 
Boulder Dam, and made clear to anyone who could understand it! 
how the atoms are arranged and deployed and linked in such a tremen- 
dous molecule as MgN4C5oH72Os. 

To Otto and Alfred and Mort every jot and joint in the vast Rube 
Goldberg machinery of that structural formula had meaning, and more 
ehan meaning the geometrical beauty of the one right, inevitable position 
for every atom. To me, a botanist's apprentice, a future naturalist, there 


was just one fact to quicken the pulse. That fact is the close similarity 
between chlorophyll and hemoglobin, the essence of our blood. 

So that you may lay your hand upon the smooth flank o a beech, and 
say, "We be of one blood, brother, thou and I." 

The one significant difference in the two structural formulas is this: 
that the hub of every hemoglobin molecule is one atom of iron, while 
in chlorophyll it is one atom of magnesium. 

Iron is strong and heavy, clamorous when struck, avid of oxygen and 
capable of corruption. It does not surprise us by its presence in our blood 
stream. Magnesium is a light, silvery, unresonant metal; its density is 
only one seventh that of iron, it has half of iron's molecular weight, and 
melts at half the temperature. It is rustless, ductile and pliant; it burns 
with a brilliant white light rich in actinic rays, and is widely distributed 
through the upper soil, but only, save at mineral springs, in dainty quan- 
tities. Yet the plant succeeds always in finding that mere trace that it 
needs, even when a chemist might fail to detect it. 

How does the chlorophyll, green old alchemist that it is, transmute the 
dross of earth into living tissue? its hand is swifter than the chemist's 
most sensitive analyses. In theory, the step from water and carbon dioxide 
to the formation of sugar (the first result readily discerned) must involve 
several syntheses; yet it goes on in a split hundredth of a second. One 
sunlight particle or photon strikes the chlorophyll, and instantaneously 
the terribly tenacious molecule of water, which we break down into its 
units of hydrogen and oxygen only with difficulty and expense, is torn 
apart; so too is the carbon dioxide molecule. Building blocks of the three 
elements, carbon, hydrogen and oxygen, are then whipped at lightning 
speed into carbonic acid; this is instantly changed over into formic acid 
the same that smarts so in our nerve endings when an ant stings us. No 
sooner formed than formic acid becomes formaldehyde and hydrogen 
peroxide. This last is poisonous, but a ready enzyme in the plant probably 
splits it as fast as it is born into harmless water and oxygen, while the 
formaldehyde is knocked at top speed into a new pattern and is grape 
sugar, glucose. And all before you can say Albert Einstein. Indeed, by 
the time you have said Theophrastus Bombastus Aureolus Paracelsus von 
Hohenheim, the sugar may have lost a modicum of water and turned 
into starch, the first product of photosynthesis that could be detected by 
the methods of fifty years ago. 

At this very instant, with the sun delivering to its child the earth, in 
the bludgeoning language of mathematics, 215 X io 15 calories per second, 
photosynthesis is racing along wherever the leaf can reach the light. (All 
else goes to waste.) True, its efficiency is very low averaging no better 


than one per cent, while our machines are delivering up to twenty-five 
per cent of the fuel they combust. But that which they burn coal and 
gas, oils and wood was made, once, by leaves in ancient geologic times. 
The store of such energy is strictly finite. Chlorophyll alone is hitched 
to what is, for earthly purposes, the infinite. 

Light, in the latest theory, is not waves in a sea of ether, or a jet from 
a nozzle; it could be compared rather to machine gun fire, every photo- 
electric bullet of energy traveling in regular rhythm, at a speed that 
bridges the astronomical gap in eight minutes. As each bullet hits an 
electron of chlorophyll it sets it to vibrating, at its own rate, just as one 
tuning fork, when struck, will cause another to hum in the same pitch. 
A bullet strikes and one electron is knocked galley west into a dervish 
dance like the madness of the atoms in the sun. The energy splits open 
chlorophyll molecules, recombines their atoms, and lies there, dormant, 
in foods. 

The process seems miraculously adjusted. And yet, like most living 
processes, it is not perfect. The reaction time of chlorophyll is not geared 
as high as the arrival of the light-bullets. Light comes too fast; plants, 
which are the very children of light, can get too much of it. Exposure to 
the sunlight on the Mojave desert is something that not a plant in my 
garden, no, nor even the wiry brush in the chaparral, could endure. Lids 
against the light plants do not have; but by torsions of the stalk some 
leaves may turn their blades edge-on to dazzling radiation, and present 
them again broadside in failing light. Within others the chlorophyll 
granules too, bun or pellet-shaped as they are, can roll for a side or 
frontal exposure toward the light. In others they can crowd to the top 
of a cell and catch faint rays, or sink or flee to the sides to escape a searing 
blast .... 

When I began to write these pages, before breakfast, the little fig tree 
outside my window was rejoicing in the early morning light. It is a 
special familiar of my work, a young tree that has never yet borne fruit. 
It is but a little taller than I, has only two main branches and forty-three 
twigs, and the brave if not impressive sum of two hundred and sixteen 
leaves I have touched every one with a counting finger. Though sparse, 
they are large, mitten-shaped, richly green with chlorophyll. I compute, 
by measuring the leaf and counting both sides, that my little tree has 
a leaf surface of about eighty-four square feet. This sun-trap was at work 
today long before I. 

Those uplifted hand-like leaves caught the first sky light. It was poor 
for the fig's purpose, but plant work begins from a nocturnal zero. When 
I came to my desk the sun was full upon those leaves and it is a won- 


drous thing how they are disposed so that they do not shade each other. 
By the blazing California noon, labor in the leaves must have faltered 
from very excess of light; all the still golden afternoon it went on; now 
as the sun sets behind a sea fog the little fig slackens peacefully at its task. 

Yet in the course of a day it has made sugar for immediate burning and 
energy release, put by a store of starch for future use; with the addition 
of nitrogen and other salts brought up in water from the roots it has 
built proteins too the very bricks and mortar of the living protoplasm, 
and the perdurable stuff of permanent tissue. The annual growth ring 
in the v/ood of stem and twigs has widened an infinitesimal but a real 
degree. The fig is one day nearer to its coming of age, to flowering and 
fruiting. Then, still leafing out each spring, still toiling in the sunlight 
that I shall not be here to see, it may go on a century and more, growing 
eccentric, solidifying whimsies, becoming a friend to generations. It will 
be "the old fig" then. And at last it may give up the very exertion of 
bearing. It will lean tough elbows in the garden walks, and gardeners 
yet unborn will scold it and put up with it. But still it will leaf out till 
it dies. 

Dusk is here now. So I switch on the lamp beside my desk. The power- 
house burns its hoarded tons of coal a week, and gives us this instant and 
most marvelous current. But that light is not new. It was hurled out of 
the sun two hundred million years ago, and was captured by the leaves 
of the Carboniferous tree-fern forests, fell with the falling plant, was 
buried, fossilized, dug up and resurrected. It is the same light. And, in 
my little fig tree as in the ancient ferns, it is the same unchanging green 
stuff from age to age, passed without perceptible improvement from 
evolving plant to plant. What it is and does, so complex upon examina- 
tion, lies about us tranquil and simple, with the simplicity of a miracle. 


This earth, this third planet from the sun, was lifeless once. The rocks 
tell that much. There is one place in the world where the complete 
record is written on a single stone tablet. The Grand Canyon of the 
Colorado River is a cross section of geologic time. Cut by a master hand, 
the testimony appears to our eyes marvelously magnified. The strata burn 
with their intense elemental colors; they are defined as sharply as chapters, 
and the book is flung wide open. A silver thread of river underscores the 
bottom-most line, the dark Vishnu schist where no life ever was. 

Mother-rock, these lowest strata are aboriginal stuff. They are without 
a fossil, without a trace of the great detritus of living, the shells and 
shards, the chalky or metallic excreta of harsh, primitive existence. These 


pre-life eras have been past for a long time two billion years, perhaps. 
Perhaps a little more. Astronomical sums of time are so great that they 
bankrupt the imagination. We listen to the geologists and physicists 
wrangling over their accounts and compounding vast historical debts 
with the relish of usurers, but it is all one to us after the first million years. 

No matter here how they arrived at their calculations. As plantsmen we 
are interested in the moment when the first plant began. For there was 
raised the flag of life. 

The first life on earth I have no doubt of it was plant life. Any 
organism that could exist upon a naked planet would have to be com- 
pletely self-supporting. It would have to be such a being as could absorb 
raw, elemental materials and, using inorganic sources of energy, make 
living protoplasm of them. Such describes no animal. But it perfectly 
describes an autotrophic plant. An autotroph is a self-sustaining vital 

The geologist's picture of the younger stages of this our agreeable planet 
home resembles the Apocalyptic doom for the world that I once heard 
predicted to innocents in a Presbyterian Sunday School. For the geologist 
sees flaming jets of incandescent gas, bolts and flashes that, condensing 
as they cooled, became a swarm of planetesimals, fragments comparable 
to great meteoric masses of stone and metal. These, by all the rules of 
orthodox astronomy, must rush together whenever their orbits came too 
close. So, by shocking impacts, the world was slapped together at random. 
It grew snowball fashion. It probably grew hotter, rather than cooler, 
from the friction and energy of the collisions, and the increasing pressure 
on the core must have generated a heat to melt the heart of a stone. So, 
in a molten state, the heaviest elements sank to the gravitational center, 
and formed the lithosphere terra firma itself while the lightest rose to 
become the atmosphere. 

That atmosphere, it is presumed, was far, far thicker than it is today. 
It was perhaps hundreds of miles high, and may have had an abundance 
of now rare gases, like helium and hydrogen, neon and argon, and 
possibly even very poisonous gases, sulphur-drenched vapors, deadly 
combinations of carbon with oxygen, of oxygen with nitrogen. Almost cer- 
tainly there was much less free oxygen and free nitrogen and carbon di- 
oxide, than now, and correspondingly little scope for life as we know it. 

But dense mists of water vapor, of steam clouds forever moiling and 
trailing about the stony little sphere, there must have been. For the 
oceans were, presumably, all up in the air. Only with cooling they began 
to condense, to fall in century-long cloudbursts, filling the deeps and 
hollows. At first, perhaps, striking hot rock, they were immediately 


turned to hissing steam again. The stabilization o the oceans alone must 
have been an awesomely long affair. It is doubtful if any sunlight at all 
got through that veil of primordial cloud, and the earth, viewed from 
Mars, would have been as unsatisfactory as Venus seen from the earth 
today, for the clouds of Venus never lift. Darkness then, darkness over 
the peaks clawed by the fingers of the deluge and dragged into the 
oceans; darkness over the forming seas that were not salty and full of an 
abundant and massive life, but fresh water, like that of the present Great 
Lakes. Fresh, and empty of life, warm, and dark. Darkness, and warmth, 
and water. Dark and warm as the womb, and awash with an amniotic 

And into this uterine sea fell the seeds of life. 

The oldest fossils in the oldest of all fossil-bearing rocks, the Archaeo- 
zoic, tell six unmistakable things: 

The first organisms of which there is any record on the stone tablets 
of time were cellular, just like all modern organisms. 

They were aquatic, like all the most primitive organisms. 

They were plants, unmistakably. 

They were microscopic. 

And they were bacteria. 

Of course these were bacteria of a very special sort. Not in the least like 
the germs that cause diseases of man or those useful scavengers, sapro- 
phytes, that break up dead plant and animal remains and excreta. For 
these dread parasites and vulturine saprophytes are finicking and highly 
specialized. The parasites are hothouse species, most of them unable to 
endure more than a few hours outside very modern and complex bodies; 
even the saprophytes imply the presence of higher organisms to feed on. 
Not one is an autotroph. Not one sustains itself. 

No, the kind of bacteria that left their marks upon the ineradicable 
record is a sort never studied by medicine. They are autotrophs, sufficient 
unto themselves. They invade no living bodies; they are probably not 
related at all to those which do, and if one kind is bacteria, the other 
ought really to have a clear name of its own. But there is no other com- 
mon English name for them; botanists call everything "bacteria" which 
is so small that very little structure can be discerned. 

One at least of these autotrophic bacteria that lived in the dark, hot, 
fresh-water ocean, was the selfsame plant that is found today in mineral 
springs heavily charged with iron, in old wells driven through hardpan, 
in those rusty or tannic-looking brooks that seep away from stagnant 
bogs, where bog iron ore is gathering. Its name is Leptothrix. The 
Archaeozoic rocks are about one billion years old. In all that time the 


ochre Leptothrix has not changed one atom. As it reproduces simply by 
fission the splitting of one bacterial cell into two it has never died. It 
is, in body, immortal, and may outlive all other races. 

The place to look for Leptothrix is around a mineral spring. On the 
rocks, in little nubbly reefs, in the brooks running from the springs, there 
waves a yellowish-rusty slime. This has a greasy feeling to the fingers; 
it rubs away instantly to nothing. But when you tease a little out in a 
drop of water, and shove the drop, on its clean glass slide, under the lens, 
the slime comes to life. For besides a great deal of shapeless rusty blobs 
and cobwebs, there are imbedded in this mass long unpartitioned fila- 
ments or tubes. They look a bit like root hairs under low magnification, 
and are surrounded by a nimbus of slime. 

But the walls of the filament are absolutely definite; they proclaim 
organization, clear-cut form, something with the shape that only the 
living take on. And those walls of the filaments are of iron, deposited 
around the living bacterial cells by accretion. 

As for the bacterial cells themselves, they are elliptical bodies, but 
remarkable for having "tails." So, placed end to end, they look like polly- 
wogs packed into a boy's pea shooter. When overcrowded, some of the 
bacteria escape. Then by their lashing polar tails they swim free, just like 
a sperm cell of a seaweed or a mammal. Soon a fresh deposit of iron settles 
around them. As it lengthens, daughter cells come to fill it, by fission of 
the mother-cell. 

Actual living Leptothrix colonies fully charged with active bacteria are 
not especially easy to find. Often one hunts for hours on bacterial slides, 
encountering only empty sheaths. But their fossil imprint is particularly 
sharp and unmistakable. And the sheaths, being iron, and not living 
matter subject to decay, have long lasting powers. Thus in the iron- 
charged waters that overlay some of the most ancient of rocks, Leptothrix 
flourished for countless dark ages, slowly, slowly dropping the detritus 
of its outworn shards, building up an ooze that, under the terrific pressure 
of the water above, became iron ore. 

But how, it is right to ask, was Leptothrix able to live without photo- 
synthesis? How was it nurtured in a water that contained few or none 
of sea water's rich salts of today, but only a bitter diet of iron compounds? 

Leptothrix lived then, as it does today, by oxidizing iron. When we 
oxidize carbon (burn coal) we release enough energy to turn all the 
mills of the world. When oxygen rushes into the lungs of an asphyxiated 
man, his anemic blood is refreshed; his eyelids flutter, he comes to life. 
Life is one vast oxidation, one breathing and burning. Man and his 
beasts are fueled by the plants; the plants consume the earth stuff they 


built up by their green sun-power; but Leptothrix, aboriginal, microscopic 
Leptothrix, taps atomic energy. It literally eats iron. 

Such is chemosynthesis, contrasted with photosynthesis. In a darkened 
world of water, chemosynthesis was then the only possible synthesis or 
assembling of materials into life and how effective it was for how long 
can be judged from the work of Leptothrix in the waters that once rolled 
above the Mesabi range, north of Lake Superior. This iron seam, believed 
to be largely the work of iron bacteria depositing a subterranean reef, is 
called by engineers simply "The Range," for beside it there is no other 
comparable. It is the range of all iron ranges, and so great and so heavy 
is the ore yearly moved out of it, that the locks of the Sault canal, though 
open only six or seven months of the year, and having a traffic deeply 
loaded only on the out voyage, transmit more tonnage than any other 
canal in the world, excepting none. . . . 

Others of these element-consuming bacteria oxidize carbon or hydrogen 
or nitrogen or ammonia or marsh gas. When they combust this last, then 
the will-o'-the-wisp dances over the bogs. Still another has manganese for 
its staff of life. Manganese, by the way, is an alloy of the steel used to 
burglar-proof safes. But it is no proof against the microscopic, hard- 
headed Cladothrix. Variously we are being used or served by these 
masters of a fundamental and simple way of life, the autotrophic bacteria. 
Some of them have holdfasts, like a kelp or rooted waterweed, so that 
instead of floating at random, they can grow forest-wise in the waters 
they inhabit. These enter water pipes and vegetate there, like some flaccid 
but indomitable eel-grass in a stream, till the pipes are wholly stopped. 

Of the bacterial autotrophs one you may smell on the air, and the odor 
is very like that of rotten eggs. For this one (and its name, if you like, is 
Beggiatoa) battens upon brimstone. It lives in the mud of curative baths, 
and grows in sulphur springs, and by building up a slimy reef it makes 
a bowl about some geysers, enduring and even luxuriating in a zone of 
their waters that is hot but just not too hot for it. To look at, this sulfur 
bacterium is colorless. Under the lens, you may see its strands slither, 
slipping over each other in a perpetual undulant motion with the indif- 
ference of a knot of bored snakes. 

Now, this ill-smelling Medusa is important to all of us alive here. Not 
so much because it is sometimes implanted by engineers in septic tanks 
as a valuable destroyer, as because of its greed for the sulfur on which 
it lives. It is after sulfur everywhere, anywhere, that it can get it in Nature. 

Abbreviating the chemistry of it, the result of Beggiatoa's use of sulfur 
is sulfuric acid. This is combined with the limes of the soil, creating a 
compound of calcium and sulfur that is exactly the fertilizer for which 


all roots are hungering. They do not use, they can not absorb, the sulfur 
and sulfurous compounds around them until Beggiatoa has produced 
this particular form of it. 

And living protoplasm must have sulfur, especially for its nucleus. 
Just a pinch of this mustard among the elements but that pinch is indis- 
pensable to the cuisine. So Beggiatoa unlocks for all the rest of life this 
invaluable yellow ingredient. 

All these autotrophs, with their strange diets and their labor in the 
dark, are without color. But there is one more autotrophic group which 
catch the attention because they are pigmented. And the pigments, 
although not usually green, are photosynthetic. 

The red or purple bacteria must, then, have light for their work. 
Equally, they must not have free oxygen, for it is fatal to them. When we 
cultured them in the old Agassiz laboratory, we filled the flask to the 
brim with water, stoppered it against air, and put it in the sunshine at 
the window. There photosynthesis began. 

How, since here was no chlorophyll? The answer refers the imagination 
to antiquity. The pigment of the reds or purples is called bacterio- 
purpurin, and I don't think anyone knows very much about it, but this 
much is plain to any mind: bacterio-purpurin (the red) is the comple- 
mentary color of chlorophyll (the green). So these two utilize just the 
opposite parts of the spectrum. Imagine, then, that murky and chaotic age 
of the world, when sunlight was probably of quite another quality than 
this upon my desk today, and filtered many of the rays that make so gay 
the little patio garden beyond the window. What used that strange sun- 
light, what toiled even then at the beginning of the industry that is the 
world's greatest, may have been must have been the purple bacteria. 

Early as these purple laborers were at the mighty business, those pallid 
brother autotrophs, the iron and sulfur bacteria were, I think, earlier still. 
For they required not even the tool of light. They were already active 
in the day of darkness, in the beginning of things. It is difficult to picture 
any earlier form of life. . . . 


So in the beginning of things life here on earth must have been, after 
all, Adamite a single, simple kind of organism. 

Whether that first-life was bacterial, or algal, or some sort of spon- 
taneous colloidal protein system that began to live, this planet in 
Archaeozoic times (estimated at one to two billion years ago) was so 
impoverished as to variety that a full account of its flora and fauna, if 
anywould make a paper so concise, so lacking in disputatious matter and 


naked of footnotes that a right-thinking college faculty would scarcely 
accept it as a doctoral thesis. . . . 

Precisely because life is pliant and fluid, it is also, like water, most 
difficult to maintain in any shape it does not wish to take. And very hard 
it is to turn life from the channels that it has itself grooved deep. The 
resilience of life is probably the strongest thing in the universe. For 
though the mineral kingdom is vast and mighty, with the abrupt flinty 
hardness of all reality, it is for that very reason rigid. And because it is 
rigid, the mountains can do no other than stand still and let the lichens 
leach them, the delicate mosses pry them open with exquisite fingers, the 
invisible bacteria riddle them, and the rain and wind reduce them to dust. 

But you can batter a seaweed on the reefs for twice ten million years, 
without changing its inner convictions. All that the surf has been able to 
accomplish in these eons is to knock the spores out of the slippery fronds 
and so set them adrift to colonize some other reef. 

Yet there have been changes in the Green Kingdom, sweeping changes, 
far-reaching in their consequences to all of us animals, to the very crust 
of the planet we inhabit and, literally, to the air we breathe. Were it not 
for these changes, which we call evolution, no lily would rise from the 
muck, no alder shake pollen from its curls in the March wind. 

The significant fact is that all the really great changes have come from 

the inside out. They are born of the inner nature of the organism itself. 

They must have lain there, inherent as a possibility (more, as an irre- 

jpressible necessity) in the first Adamite organism, just as a tall pine is 

potential in a soft pinyon seed no larger than a child's tooth. 

These changes are the history of the Green Kingdom. It is a history with 
as many dynasties and disasters as the history of China, though I find it 
much easier to remember than the long singsong of the wars and rulers 
of Cathay. But, like the history of a very ancient people, the story of 
plants on earth shows the antiquity of things called modern. As China 
invented tools of civilization and forgot them again, as it piled up annals 
and archives for hundreds of years, and lost them in a dark age or through 
the whim of a bibliophobe ruler, so in the plant kingdom almost every 
scheme has been tried once, or many times. 

In every part of the sea and on every continent, life has set up one green 
stage set after another, taken it down, shipped it elsewhere, put up a new 
one. Giant seaweeds were rolled into beach wrack, fossilized sometimes 
into great stone dumplings, where now the corn of Illinois stands high, 
the chaff of threshing blows in the hot sun, and the soul longs for the sea. 
Sixteen times the sea came and went there, alternating with lofty fern 
forests. A resinous grove of pine-like trees thrust deep, reached high, 


where now the Papago Indian cuts a cactus to cup in his dark hands one 
luke-warm drink against the Arizona sun. And the petrified slab of a 
vanished tree that lies on my desk shows its every smallest cell exactly 
replaced by a crystalline mineral, as if the Medusa had looked upon that 
classic wood. 

This tale of the rise and fall of the dynasties of growth must be pieced 
out of the rocks and fitted together with a strong and cementing likeli- 
hood. Fossil records make up our fragmentary evidence. It is all held 
together by the assumption that life began as something simple and 
adapted to easy conditions, and progressed toward fitness for the conquest 
of more hostile environments. The inferences from this assumption are 
borne out by the fossil record, such as it is. 

What that record is, and is not, Darwin expressed when he said that 
the story of life is written in a book whose language or code changes with 
every chapter, and of which all but a few pages have been lost, the little 
that remains being scattered to the ends of the earth and senselessly 

So every fossil on a museum shelf is a three-fold miracle. First, the 
plant had to die under the most exceptional conditions remote from the 
normal course of events, which is swift decay, dissolution, and reworking 
of the mold into new forms of life. Then, by a wildly fortuitous set of 
circumstances, the fossilized evidence must not be washed into the sea, 
or buried several miles under sedimentary rocks, but had to come to light, 
be bared by erosion, or deprived of its Stygian privacy in the course of 
mining or excavating. And then, as the most unlikely chance of all, a 
paleobotanist (a very rare fellow even in a densely packed congress of 
botanists) had to pass by and collect the specimen before it was burned for 
coal, ground up for cement, washed away or otherwise hopelessly 

The longer the time elapsed, the less the likelihood that some tangible 
record will have survived. For that reason, and because the very earliest 
life was so sparse, so minute and fragile, the first rocks that could have 
borne life have almost nothing to tell us. They are nearly blank. But not 
quite. They speak, from their staggering thickness, of a measure of time 
that lasted longer than all the time that has gone by since perhaps twice 
as long. But they speak of life. 

To judge from the bacterial traces in them, life was tediously slow in 
gathering momentum. The little earth flew around the sun in its annual 
course millions and millions of times, and the sun on its unguessable 
track had plunged unthinkable distances into space, before much change 
had come about in those first vital experiments. We were in some other 


quarter of the universe; our sun appeared, from the viewpoint of other 
stars, to belong to some constellation from which it has now fallen, while 
the bacteria were leisurely taking the calcium carbonate out of the sea 
water and depositing it in the oceanic oozes, as the minute and brief lives 
perpetually and vastly died. And, as they laid down the great limestone 
beds, over the acid and sterile granites, so on land they were, surely, 
delving into the rocks. Bacteria have been brought up from borings five 
hundred and even fifteen hundred feet below the surface. So they have 
riddled and mollified the rocks and prepared the loams. 

And as surely as they were altering their environment, the bacteria were 
themselves changing. Not that they were, as a race, departing, for their 
seed is still upon earth, the most numerous, important, and likely to out- 
last the ages. But they were giving rise there seems little doubt of it 
to the blue-green pond silks you see today still in stagnant waters. 

These Blue-Green algas, just visible to the naked eye as shaky strands in 
a ditch, or the merest cast of jade across a lily pond, are the second 
chapter in plant history. It can be read only with a microscope, and it 
happens that I opened at its pages, in those primer days when I was given 
my first fine lens. This microscope was not new nor particularly con- 
venient, but it was originally the best from a good factory of lens makers. 
It was given me, in those young plant hunting days in the Carolinas, 
by a woman naturalist who had used it to study bees and pollen. I remem- 
ber how she put it in my hands with a silent blessing on my enthusiasm 
and a dry smile at its scope. 

As soon as I got it home, I gently opened that case so like a traveling 
shrine, and drew forth the stately and intricate image, itself the god that 
sees what is hidden. Then I went out to the ditch across the road and 
scooped up a saucer full of pond silks. With pipette I snuffled up a long 
drop of water and green tress, lowered a little on a slide, and sealed it 
with a cover-glass. I was very serious about my technique, and I knew 
enough, at least, to realize that the Algae are a great and a right beginning. 

My eye to the shaft, I lowered the lens by the big wheel almost to the 
slide, peered in, rolled it slowly up, and saw the algal jungle come clear 
but distant. Then I snapped in the high power and began, with the fine 
wheel, to hunt for the focus again. 

First there was a green blur; then, as a falling aviator must, I saw the 
green tops of the forest rush upward, come clearer, nearer, till I was in it 
and plunging through the top storey into lower tiers. I held my hand 
and suddenly there was life the first living microscopic forms I had 
ever seen, and green with the good green of the great kingdom. No 
bacteria here, no unearthly and devious modes of living, but chlorophyll, 


and clear cellular form. As it was a water forest, a sargassum, it was hori- 
zontal, the jetsam of a micro-sea. I began to revolve the stage itself, and 
felt like a Magellan. . . . 

The Algae love the damp, the stagnant ponds, the rolling ocean. 
They are, historically speaking, children of the sea, ancients of the first 
watery world, so much older than the Rockies that when those moun- 
tains were buckled up in a continental camp, their limestones carried up 
with them fossilized seaweeds two miles into the air. Even today, whether 
they go down into the earth or up to the glacial snows, the Algae are still 
wherever you find them aquatics. Somehow they divine a thread of 
water or a mere film of it. So from that primal fresh-water sea in which 
they were born, they have invaded the modern brine and the drying con- 
tinents. They are found in snow and on flower pots, in the coruscating 
soda of shrinking desert lakes, whether in Tartary or Utah, in hot springs 
of New Zealand and Iceland, in sponges and the toe hairs of tree sloths 
and on the legs of a Russian tick. They are collected on Antarctic ice and 
from the roots of cycads in tropical rain forests. I have seen them where 
they form an unholy fluffy felt in the muck of slum yards, and I have 
looked down from the top of a skyscraper, in a wilderness of steel and 
stone, and seen their flagrant green in the lily pond of a penthouse 

Once you begin to think about algas, and to look for them, you see 
them everywhere. The Blue-Green Algae look, and are, slimier than the 
Green. Many are poisonous; most are associated with polluted water; 
their presence indicates something unhealthy for us. They are the sort 
of organisms that Aristotle, peering into his "primordial slime," con- 
ceived as originating from the mud itself. But all these qualities only serve 
to show from how far they have come from a fabulous age and an 
earth that would have been uninhabitable for us, when the seas were not 
salt and the continents were brimstone, and the very sun looked down 
with a different light in its eye. 

For the blue pigment of the Blue-Greens, adapted no doubt to capture 
solar energy also in a different part of the spectrum, masks the raw 
green chlorophyll. True that the Blue-Greens flourish in modern sun- 
light but only in their gelatine sheath. Deprived of that, they are killed 
by direct light, just as bacteria are. Indeed, these Blue-Green Algae are 
next in seniority to the autotrophic bacteria, and resemble various of them 
significantly. In their filamentous or spherical shape, for instance, their 
slimy sheaths, their slow creep or oscillation. Too, they are devoid 01 
starch, that stored wealth for man and beast, which pervades most of the 
rest of the plant kingdom. And the Blue-Greens, be it noted, are, like the 
bacteria, devoid of any sexual type of reproduction. 


But they have chlorophyll, they have set up in the great photosynthetic 
business, and like all green water plants, they give off bubbles of oxygen. 
As presumably the Blue-Greens throve in the warm, fresh seas of ancient 
time, so some to this day live only in hot springs, whether at Rotorua 
geyser in New Zealand, or our own Yellowstone. Endlessly rising and 
dying, they deposit the weird sinter that makes the basins of the geysers 
so picturesque, and they build up a sort of rubble or tufa, or become 
solidified to an onyx-like travertine rock. 

Or some Blue-Greens cause the "water-bloom" on pools, sometimes 
identified by botanists as Aphanizomenon but known as "Fanny" by the 
engineers who try to get rid of it, for it is fatal to cattle, with an unknown 
poison. Some Blue-Greens are more red than green, and one of them, 
prodigiously multiplying in the water between two deserts, has given the 
Red Sea its ancient name. 

It is like crossing the frontier into a friendly country, to leave the Blue- 
Greens for the true Greens. As they form part of the grazing for so many 
aquatic small fry that feed the big ones, they are indirectly useful to us; 
they are the pasturage biologists call it the plankton of all the waters 
that can sustain them. And the Greens are, as they leave the reaches in 
which they resemble the bacteria-like Blue-Greens, honest plants such as 
we can better understand. They do their work by clear chlorophyll, and 
store starch and fats as higher plants do, and are built up of cellulose and 
pecten just as are the most aristocratic trees. And, save for the most 
primitive, the Greens have sex. They may be said, indeed, to have 
originated it. 

That plants share sex with the animal kingdom is one more proof of 
the oneness of life. Yet mankind was a long time in perceiving the obvious. 
The ancients grew figs and olives, apples, peaches and chestnuts, as well 
as daughters, and saw that in youth their trees were barren, that they came 
to flower at a certain age, and fulfilled their purpose when they bore 
their fruit. And still men did not draw the simple parallel. The idea of sex 
in plants was scarcely proposed until the seventeenth century and accepted 
in the eighteenth only after furious opposition even from scientists. 

And its purpose appears (since there are many, and very effective, non- 
sexual ways in which plants can reproduce themselves) to be the renewed 
vigor that comes with the conjunction of individual strains of protoplasm. 
Along with that refreshment of vital energy, there is implied the com- 
mingling of separate hereditary strains. Non-sexual reproduction endlessly 
multiplies the old individual, with all its virtues or weaknesses. But in a 
world of beings sexually divided, sexually united, enrichment is infinite, 
permutation endless. So evolution, slow to gather momentum, discovering 


the device of sex in the Green Algae swept forward upon its indomitable 
and unpredictable flood tide. 


Over my study mantelpiece, where the barometer and the great triton 
shells repose, is stretched the big sailing chart of this California coast 
on which I live. Worked intricately as a thumb-print with soundings and 
fathom lines, it shows the edge of the continent cutting across the upper 
right-hand corner, and off shore, in the currents, the islands of the Santa 
Barbara Channel. On clear days from my veranda, through an arch of 
live-oaks I can see them rise, abrupt and purple-shadowed. For they are the 
tops of an old mountain chain, and so upon the map they lie singularly 
alike in shape, very much like a flight of cormorants migrating parallel 
to the mainland. My eyes, so often lifting from my desk to seek them, find 
them there stretching out long goosy necks that bear small heads, or, as 
if foreshortened, they appear to sail upon wings edge-on. They hold the 
Channel in a light embrace; outposts of terra firma in the wilderness of 
sea, they temper it to inhabiting life. 

On a fair day the Channel glitters azure, emerald-streaked where the 
sea is so thick with the life it bears that it refracts the sunlight, red with 
the moiling kelp beds, purpled by a passing cloud. Shallow, as biological 
fathoms are reckoned, deep as the angler thinks of depth, dark with the 
Kuro Shiwo stream that has crept here in a mighty arc from Japan. 

Here off the tawny continental flank, in the lee of Santa Rosa, Santa 
Cruz, San Miguel, sleeps the Pacific from May until December. The broad 
ruddy band of the kelp beds, well off shore, never changes place. These 
giant kelps of the California coast are the largest in the world. Elk kelp 
and sea-otter's cabbage and the iodine kelp have dimensions of forest trees. 
Forty and sixty feet deep they are rooted by suckering holdfasts; their 
stems, flaccid but tough, may attain two hundred, three hundred feet in 
length. Their foliage is ample and heavy as the leaves of a rubber tree; 
they are buoyed up by double rows of bladders, or sometimes by a single 
float the size of a grapefruit. Some, like the trees of earth, are permanent 
perennials; in others which are annuals this leviathan growth is the work 
of a single season. Upon these towering, wavering Algae the Browns 
perch countless others, as the lianas and orchids cling upon the boughs 
of the over-earth tropical forests. For the most, these clinging frailties are 
Reds, and there are others of them, membranous and filigreed, that trem- 
ble on the ocean floor beneath the shelter of the lofty Browns, like moss 
and ferns that hug the ground between great roots. Such is the ocean 


jungle. It hangs such leathery curtains of foliage in the water and is 
flung abroad like an undulant carpet so wide upon the surface, that the 
fall and swell of the ocean's breathing is stilled by it. Within this 
breakwater, the seas lie harbor calm. 

Beneath, in the depths of the great kelp forest, the small fry dash for 
shelter, in terror of swordfish and albacore and tuna. Here the crabs 
nibble the algal pasturage, and the sea slugs, which mimic the colors of 
the vegetation, crawl and mouth, and the kelp fish builds her nest of woven 
weed. Above these beds, all summer, in a leisure that gives thieves time 
to fall out, the gulls quarrel and rise, to settle again with a twinkling of 
sunlit wings. Brown pelicans plunge there; black cormorants from the wild 
Farallones fish these banks; loons dive with an oily ease, and sometimes a 
heron stands upon the buoyed kelp tops, gazing morosely into the water. 
Day after day only calm and sunshine, kelp and fish and birds. Boats 
give the beds a wide berth, for fear of the weed in their propellers; 
fishermen hate it in their nets. No swimmer who loves his life would dive 
in that sargasso of the great Browns, nor could he endure the pressure of 
the deeps where the most fragile of all the Reds delight to live. The 
Browns, with their special pigments masking the chlorophyll, go down in 
the seawater till the orange and the yellow light have been filtered out. 
But the Reds can carry on their photosynthesis four hundred feet below 
the surface, where even the green and blue light fails, and only the violet 
rays still reach the delicate mechanism. In such secrecy dwell fragile 
perennials and summer annuals that live and die and are not seen by men, 
it may be, for years. 

But halcyon weather, even here, cannot always endure. The winter 
rains come finally, and some night, after a day of grey brooding, they 
begin as a scamper of drops across the roof, a wind-blown hail of acorns, 
then a dance of rain, that becomes a ceaseless march. It rains till the dry 
arroyos run again; it rains till the rocks roll down the brooks; it rains till 
the hills begin to slide, and yet it has only begun to rain. 

In January the first storm approaches. It gathers on the north Pacific, 
and sweeps down even into the Channel's shelter. It troubles the seaweed 
forest, then twists it and tortures it, and pulls it by the roots and breaks it. 
The annuals come up, then the permanent growth. The living break- 
water is broken with the waters; it is dragged up to the top, rolled in the 
green jaws of the combers, and flung, fighting and slithering back in 
vain, on the rocks, and pounded there. The rising tide carries it, a helpless 
wrack, to the high beach where it must bleach and rot. 

After such a storm I lately came to the shore. The sea was mild in a 
warm sun; sails languished on the fishing banks; gulls were back on the 


kelp, and the kelp was back in its place, of? shore, all but the loot flung 
up, not yet reclaimed by an incoming tide. 

High up under the rocks, the giant kelps and tangs were thrust into 
an untouchable mound of decay that was waist high. Lower on the 
strand lay the lighter jetsam, the small Browns and the many Reds, in 
windrows tangled with eel grass and surf grass. Already these frail lives 
of the deep were passing swiftly, blanching or blackening. For them, this 
sunny air was a world too harshly illuminated, too arid for life. 

But in the tide pools where they had been flung with sea urchins and 
starfish, they still lived, floating out with a vitality like the moving hair 
of the drowned. There I lifted wavering membranes of the edible Por- 
phyras and the scarlet tousle of Plocamiums, filigree and point lace, fluted 
ribbons and lappets, sea-mosses as dark as the branching stains in agate, 
filmy ferns that lay upon my palm as insubstantial as the impress of a 
fossil growth. They were so unbelievably thin that when I had mounted 
them on stiff white paper they passed, with those who saw them, for the 
stroke of a water colorist's brush. 

For I carried home a vasculum full of seaweeds, and with my fingers 
under water coaxed them all apart. When I had disengaged every filament 
and swept it clean of grit and parasites with a fine brush, my ocean algas 
emerged as lovely as are flowers. Botanically it was possible to assort and 
classify them among the major types, called roughly the Greens and Reds 
and Browns. But the colors were subtler than that. They were seashell 
pink and sunset rose, saffron and Tyrian and smoke-velvet, tannic wood- 
red, lake, carmine, verdigris, Spanish green, olive, maroon, garnet and 
emerald. Only cathedral windows have such soft and glowing stains. . . . 

Of all algal morasses and there are great ones on the north coast of 
Norway, in the fjords of Alaska, around New Zealand and the Great 
Barrier reef, off Good Hope and Cape Horn the most fabulous is the 
Sargasso Sea. Sargassum, the Gulf weed, is not, individually, a conspicu- 
ous plant. It looks rather like a sprig of holly, with crinkly leaves and 
gas-filled bladders that might be mistaken for berries. Rather, the sheer 
mass has given rise to the legend that ships, from the time of Columbus, 
have become entangled in its gigantic eddy of stagnation and are still 
wedged there, rotting at Lethe's wharf. It is certainly so dense at times 
that a row boat is unable to make progress and has sometimes to be 
hauled back to the mother ship. 

It harbors untold billions of microscopic animals and plants, hydroids 
that look like feathers, colonial creatures that resemble moss, and mol- 
luscs, crabs, shrimps, seahorses, pipe-fish and other small fry without end. 
Above all the Sargasso has been discovered to be the long unknown 


resort of the eels, who migrate here, mate, and die, and here their young 
mature to the elver stage before they begin their incredible journey to 
their parent rivers and ponds in the interior of Europe and America. 

The sheer weight of the Gulf weed in the Sargasso Sea has been com- 
puted at ten millions tons. It is a free-floating raft of plants, torn by 
storms perhaps, from its mooring somewhere in the Gulf of Mexico and 
the Caribbean and caught in the eddy of the Gulf Stream and Equatorial 
counter-current. Yet one looks in vain for gigantic gardens that could 
supply such an assemblage of weed. More, this vast plant drift sometimes 
utterly disappears. So that several scientists, sailing by at such a time, have 
"disproved" the Sargasso Sea as a myth. Others who have seen it say that 
it sinks below the surface, to rise again at certain seasons. But no man 
knows. The Sargasso remains one of the ancient secrets of ocean, and it 
gives us some suggestion of what the seas were like in that period of 
geologic time that has been named the Age of Seaweeds. 

Not that then there were necessarily more, or more variety than we 
know today. But there was, except for bacteria, presumably nothing else. 
There may even have been no land above the waters for a long time, but 
only a world sea or Panthalassa. In this shallow all-ocean the algas could 
have rooted far more extensively than now. And when the continents 
arose, the seaweeds in that eon that was theirs, a time longer than that 
which has gone by since the first land plants appeared, were slowly 
evolving toward the mastery of their environment. They were adapting 
themselves to the increasing brininess of the ocean, to the conquest of the 
deeps and of the tidal shores. Perhaps it was they who first set green foot 
on shore, but of that we know nothing. 

What we do know from the book of fossils is that the seaweeds in their 
Age were developing most of the traits of plants. Starting with the slimy 
Blue-Greens and the mere hair-like Greens the algas progressed through 
branching, through the welding of filament to filament into a ribbon 
tissue, through the layer of one tissue on another so that real body and 
substance were established, till they had reached a complex structure 
differentiated into definite organs like roots, leaves, stems, spore-cases and 
complex sex organs. The life history of some of the highest of the Reds 
is as complex as that of an orchid or a pine. In beauty and color some 
Algae are, indeed, flowers of the sea; others, in bulk and height and 
foliage, are the trees. 

And some of these early comers have even built the land we walk on. 

Their surfaces encrusted with lime, they have, by their endless living 
and dying, created reefs and atolls, isles and peninsulas, and even great 
limestone blankets of the continents. Animal corals get all the credit for 


such architecture; the coralline Algae and others of the stony little sea- 
weeds have probably done full half the work. Taking on the forms of 
flat, crusty lichens, of stony feathers, of brittle jointed pink lobster feelers, 
of minute mermaids' fans and mermen's shaving brushes, glove fingers 
and tremulous green toadstools, these calcareous masons are growing 
today beneath the clear waters of the Bay of Naples, the Great Sound of 
Bermuda, the reef of Funafuti, the stagnation of the old moat around the 
fortress at Key West. But they are only the living generation that exists 
delicately upon the bones of their ancestors of Proterozoic times, when 
layer by layer, in little swirls and knolls and bosses, they lifted the land 
above the sea, and left their fossil imprint in the rocks. 

For the most part, other kinds of Algae, alas, make wretched fossils. 
A seaweed alive is little more than an evanescent pellicle of life surround- 
ing impounded sea water; ordinarily it dies and vanishes without trace, 
except for the rare exquisite impress of some Red of a vanished age, and, 
occasionally, a great brown kelp like Nematophycus, one of the giants 
that lolled in the seas that stood then over interior Canada. Its fossil stem 
was a thing so stoutly dimensioned that it was taken, first, to be some 
ancestral sort of yew bole. 

But such as they are, the fossils of the Age of Seaweeds proclaim a 
tremendous story of conquest, the domination of an element by life. 
The sea teemed then. Yet in all that time, between half a billion and a 
billion years, the face of the rock was bare. Without land plants to give 
them browse, animals too were imprisoned in the sea, for it is a trap as 
well as a world. The Age of Seaweeds was the age of Invertebrates. Every 
order of spineless animal we know today, and many that are extinct like 
the scorpion-like trilobites, flourished in those submarine gardens or 
ranged the deeps and the open spaces. Jelly-fish and sea anemones, octopi 
and squids, hydroids and bryozoons, sea slugs and sea snails and great 
conchs, tritons, nautili, and abalones populated the algal jungles. The 
lampreys, writhing and suckering, evolved, and finally even fishes. And 
still life was wholly aquatic. On land was a harsher world, with drying 
winds, without the old maternal medium to buoy plants, to bring them 
all salts, all minerals, in its perpetual convection. But it was a much more 
stimulating environment, destined to call forth great things of life and 
lead it to triumph. Yet still on all the earth there was no flower and no 
voice; the continents were coursed by winds that blew no one any good 
and carved by rains for which there was no root or throat to be grateful. 


Three hundred and fifty million years ago is as far away as a star. To 
describe a plant that w